About Earthwork and Grading
What is earthwork and grading?
Earthwork and grading is the process of preparing a site for construction by reshaping, leveling and compacting the soil.
Construction sites must be graded so that water can flow away from buildings and other structures to avoid flooding. It also ensures even ground levels for constructing foundations. Earthwork is often accompanied with grading of landforms such as ditches, berms or embankments which are used to channel water flow away from an area. A ditch could be dug across a slope to carry surface runoff into a nearby river or stream; an embankment might be built near a roadway where it intersects with another slope in order to hold back floodwaters during heavy rainfall events. A berm may also be constructed along a shoreline next to undeveloped land in order to hold surface runoff water out of the way during construction activities.
Grading road surfaces can involve scraping or brushing off loose particles so that new bitumen, asphalt, concrete or stone aggregate can be added and compacted to form a strong, dense bond.
What is grading a site?
Grading a site involves the process of leveling the ground and moving soil to create a surface that is more even. This creates a flat construction site where a foundation for a building will be able to be laid. It also ensures water drains away from buildings and other structures to avoid flooding. Grading landforms such as hills, berms, or embankments can be done in order to channel water away from an area.
Earthwork and grading helps make construction sites safe, even, and functional for anything from residential homes to industrial plants.
What is a site grading plan?
A site grading plan is an initial plan for building a construction project. The site should be graded so that all dangers are assessed and according to regulations. The site should also be graded so that water can flow away from buildings and other structures to avoid flooding.
This includes reshaping, leveling, compacting, and preparing for construction by grading the soil in order to create a flat surface where foundations will be able to be laid. Earthwork is often accompanied with grading of landforms such as ditches or embankments which are used to channel water flow away from areas.
What is the grading process?
The grading process is the process of leveling the ground and moving soil to create a surface that is more even. This creates a flat construction site where a foundation for a building will be able to be laid.
What is the difference between grading and earthwork?
A site needs to be graded so that all dangers are assessed and according to regulations prior to construction taking place. Earthwork involves the process of reshaping, leveling and compacting soil to create a flat surface for building foundations.
What is the difference between grading and land shoring?
Land shoring is typically categorized by supporting excavation walls with wooden planks or steel piles that are driven into dirt or clay. Land shoring is limited in the amount of support it can provide. Grading and land shoring often go hand in hand, with grading done before land shoring takes place and vice versa.
What is the difference between site grading and soil erosion?
Site grading helps make construction sites safe, even, and functional for anything from residential homes to industrial plants. Soil erosion is a natural process or human-induced process of soil removal from one location on the landscape. It often leads to serious land degradation and is exacerbated by deforestation, drought, flooding, desertification and poor agricultural practices.
What is a good soil for grading?
A good soil for grading is free draining with a low water table. A sloping topography helps to divert water away from buildings and other structures.
Types of soil:
A site grading plan is an initial plan for building a construction project. The site should be graded so that all dangers are assessed and according to regulations. Before starting any type of earthwork it is key to first determine the types of soils on-site. There are three types of soils:
- Cohesive Soil - Type of soil where particles adhere together and can hold its shape when removed from the ground, also referred to as sticky soil.
- Granular Soil - A type of soil that is composed of small round pieces or particles and does not stick together in a mass when it is removed from the ground.
- Fragile Soil - A type of soil that can be easily removed in large quantities when it is dry, however when wet it becomes very strong and clay-like.
About Plain City, OH
Archeological evidence of spear points of both the Folsom and Clovis types indicate that the Ohio Valley was inhabited by nomadic people as early as 13,000 BC. These early nomads disappeared from Ohio by 1,000 BC. Between 1,000 and 800 BC, the sedentary Adena culture emerged. The Adena were able to establish "semi-permanent" villages because they domesticated plants, including sunflowers, and "grew squash and possibly corn"; with hunting and gathering, this cultivation supported more settled, complex villages. The most notable remnant of the Adena culture is the Great Serpent Mound, located in Adams County, Ohio.
Around 100 BC, the Adena evolved into the Hopewell people who were also mound builders. Their complex, large and technologically sophisticated earthworks can be found in modern-day Marietta, Newark, and Circleville. They were also a prolific trading society, their trading network spanning a third of the continent. The Hopewell disappeared from the Ohio Valley about 600 AD. The Mississippian culture rose as the Hopewell culture declined. Many Siouan-speaking peoples from the plains and east coast claim them as ancestors and say they lived throughout the Ohio region until approximately the 13th century.
There were three other cultures contemporaneous with the Mississippians: the Fort Ancient people, the Whittlesey focus people and the Monongahela Culture. All three cultures disappeared in the 17th century. Their origins are unknown. The Shawnees may have absorbed the Fort Ancient people. It is also possible that the Monongahela held no land in Ohio during the Colonial Era. The Mississippian culture were close to and traded extensively with the Fort Ancient people.
Indians in the Ohio Valley were greatly affected by the aggressive tactics of the Iroquois Confederation, based in central and western New York. After the Beaver Wars in the mid-17th century, the Iroquois claimed much of the Ohio country as hunting and, more importantly, beaver-trapping ground. After the devastation of epidemics and war in the mid-17th century, which largely emptied the Ohio country of indigenous people[dubious ] by the mid-to-late 17th century, the land gradually became repopulated by the mostly Algonquian. Many of these Ohio-country nations were multi-ethnic (sometimes multi-linguistic) societies born out of the earlier devastation brought about by disease, war, and subsequent social instability. They subsisted on agriculture (corn, sunflowers, beans, etc.) supplemented by seasonal hunts. By the 18th century, they were part of a larger global economy brought about by European entry into the fur trade.
Some of the indigenous nations which historically inhabited Ohio included the Iroquoian, the Algonquian & the Siouan. Ohio country was also the site of Indian massacres, such as the Yellow Creek Massacre, Gnadenhutten and Pontiac's Rebellion school massacre. After the War of 1812 when Natives suffered serious losses such as at Tippecanoe, most Native tribes either left Ohio or had to live on only limited reservations. By 1842, all remaining Natives were forced out of the state.
During the 18th century, the French set up a system of trading posts to control the fur trade in the region. Beginning in 1754, the Kingdom of France and Kingdom of Great Britain fought in the French and Indian War, with various Native American tribes on each side. As a result of the Treaty of Paris, the French ceded control of Ohio and the remainder of the Old Northwest to Great Britain in 1763.
Prior to the American Revolution, Britain thinly exercised sovereignty over Ohio Country by lackadaisical garrisoning of the French forts. Just beyond Ohio Country was the great Miami capital of Kekionga which became the center of British trade and influence in Ohio Country and throughout the future Northwest Territory. By the Royal Proclamation of 1763, British lands west of Appalachia were forbidden to settlement by colonists. The Treaty of Fort Stanwix in 1768 explicitly reserved lands north and west of the Ohio as Native lands. British military occupation in the region contributed to the outbreak of Pontiac's War in 1763. Ohio tribes participated in the war until an armed expedition in Ohio led by Colonel Henry Bouquet brought about a truce. Another colonial military expedition into the Ohio Country in 1774 brought Lord Dunmore's War, kicked off by the Yellow Creek massacre in Ohio, to a conclusion. In 1774, Britain passed the Quebec Act that formally annexed Ohio and other western lands to the Province of Quebec in order to provide a civil government and to centralize British administration of the Montreal-based fur trade. The prohibition of settlement west of the Appalachians remained, contributing to the American Revolution.
By the start of the American Revolutionary War, the movement of Natives and Americans between the Ohio Country and thirteen colonies had resulted in tension. Fort Pitt in Pennsylvania had become the main fort where expeditions into Ohio started. Intrusions into the area included General Edward Hand's 1778 movement of 500 Pennsylvania militiamen from Fort Pitt towards Mingo towns on the Cuyahoga River, where the British stored military supplies which they distributed to Indian raiding parties; Colonel Daniel Brodhead's invasion in 1780 and destruction of the Lenape Indian capital of Coshocton; a detachment of one hundred of George Rogers Clark's men that were ambushed near the Ohio River by Indians led by Joseph Brant in the same year; a British and Native American attack on the U.S.' Fort Laurens; and the 1782 detainment and murder of 96 Moravian Lenape pacifists by Pennsylvania militiamen in the Gnadenhutten massacre.
The western theatre never had a decisive victor. In the Treaty of Paris in 1783, Britain ceded all claims to Ohio Country to the new United States after its victory in the American Revolutionary War.
The United States created the Northwest Territory under the Northwest Ordinance of 1787. Slavery was not permitted in the new territory. Settlement began with the founding of Marietta by the Ohio Company of Associates, which had been formed by a group of American Revolutionary War veterans. Following the Ohio Company, the Miami Company (also referred to as the "Symmes Purchase") claimed the southwestern section, and the Connecticut Land Company surveyed and settled the Connecticut Western Reserve in present-day Northeast Ohio. Territorial surveyors from Fort Steuben began surveying an area of eastern Ohio called the Seven Ranges at about the same time.
The old Northwest Territory originally included areas previously known as Ohio Country and Illinois Country. As Ohio prepared for statehood, the Indiana Territory was created, reducing the Northwest Territory to approximately the size of present-day Ohio plus the eastern half of the Lower Peninsula of Michigan and the eastern tip of the Upper Peninsula and a sliver of southeastern Indiana called "The Gore".
The coalition of Native American tribes, known as the Western Confederacy, was forced to cede extensive territory, including much of present-day Ohio, in the Treaty of Greenville in 1795.
Under the Northwest Ordinance, areas could be defined and admitted as states once their population reached 60,000. Although Ohio's population was only 45,000 in December 1801, Congress determined that it was growing rapidly enough and accelerated the process via the Enabling Act of 1802. In regards to the Leni Lenape natives, Congress decided that 10,000 acres on the Muskingum River in the present state of Ohio would "be set apart and the property thereof be vested in the Moravian Brethren ... or a society of the said Brethren for civilizing the Indians and promoting Christianity".
Rufus Putnam served in important military capacities in both the French and Indian War and the American Revolutionary War. He was one of the most highly respected men in the early years of the United States.
In 1776, Putnam created a method of building portable fortifications, which enabled the Continental Army to drive the British from Boston. George Washington was so impressed that he made Putnam his chief engineer. After the war, Putnam and Manasseh Cutler were instrumental in creating the Northwest Ordinance, which opened up the Northwest Territory for settlement. This land was used to serve as compensation for what was owed to Revolutionary War veterans. Putnam organized and led the Ohio Company of Associates, who settled at Marietta, Ohio, where they built a large fort called Campus Martius. He set substantial amounts of land aside for schools. In 1798, he created the plan for the construction of the Muskingum Academy (now Marietta College). In 1780, the directors of the Ohio Company appointed him superintendent of all its affairs relating to settlement north of the Ohio River. In 1796, he was commissioned by President George Washington as Surveyor-General of United States Lands. In 1788, he served as a judge in the Northwest Territory's first court. In 1802, he served in the convention to form a constitution for the State of Ohio.
On February 19, 1803, U.S. President Thomas Jefferson signed an act of Congress that approved Ohio's boundaries and constitution. However, Congress had never passed a formal resolution admitting Ohio as the 17th state. Although no formal resolution of admission was required, when the oversight was discovered in 1953, as Ohio began preparations for celebrating its sesquicentennial, Ohio congressman George H. Bender introduced a bill in Congress to admit Ohio to the Union retroactive to March 1, 1803, the date on which the Ohio General Assembly first convened. At a special session at the old state capital in Chillicothe, the Ohio state legislature approved a new petition for statehood which was delivered to Washington, D.C., on horseback, and approved that August.
Ohio has had three capital cities: Chillicothe, Zanesville, and Columbus. Chillicothe was the capital from 1803 to 1810. The capital was then moved to Zanesville for two years, as part of a state legislative compromise to get a bill passed. The capital was then moved back to Chillicothe, which was the capital from 1812 to 1816. Finally, the capital was moved to Columbus, to have it near the geographic center of the state.
Although many Native Americans had migrated west to evade American encroachment, others remained settled in the state, sometimes assimilating in part. Starting around 1809, the Shawnee pressed resistance to encroachment again. Under Chief Tecumseh, Tecumseh's War officially began in Ohio in 1811. When the War of 1812 began, the British decided to attack from Upper Canada into Ohio and merge their forces with the Shawnee. This continued until Tecumseh was killed at the Battle of the Thames in 1813. Most of the Shawnee, excluding the Pekowi in Southwest Ohio, were forcibly relocated west. Ohio played a key role in the War of 1812, as it was on the front line in the Western theater and the scene of several notable battles both on land and in Lake Erie. On September 10, 1813, the Battle of Lake Erie, one of the major battles, took place near Put-in-Bay, Ohio. The British eventually surrendered to Oliver Hazard Perry.
Ultimately, after the United States government used the Indian Removal Act of 1830 to force countless Native American tribes on the Trail of Tears, where all the southern states except for Florida were successfully emptied of Native peoples, the US government panicked because a majority of tribes did not want to be forced out of their own lands. Fearing further wars between Native tribes and American settlers, they pushed all remaining Native tribes in the East to migrate west against their own will, including all remaining tribes in Ohio.
In 1835, Ohio fought with the Michigan Territory in the Toledo War, a mostly bloodless boundary war over the Toledo Strip. Only one person was injured in the conflict. Congress intervened, making Michigan's admittance as a state conditional on ending the conflict. In exchange for giving up its claim to the Toledo Strip, Michigan was given the western two-thirds of the Upper Peninsula, in addition to the eastern third which was already considered part of the territory.
Ohio's central position and its population gave it an important place during the Civil War. The Ohio River was a vital artery for troop and supply movements, as were Ohio's railroads. The industry of Ohio made the state one of the most important states in the Union during the Civil war. Ohio contributed more soldiers per capita than any other state in the Union. In 1862, the state's morale was badly shaken in the aftermath of the Battle of Shiloh, a costly victory in which Ohio forces suffered 2,000 casualties. Later that year, when Confederate troops under the leadership of Stonewall Jackson threatened Washington, D.C., Ohio governor David Tod still could recruit 5,000 volunteers to provide three months of service. From July 13 to 26, 1863, towns along the Ohio River were attacked and ransacked in Morgan's Raid, starting in Harrison in the west and culminating in the Battle of Salineville near West Point in the far east. While this raid was overall insignificant to the Confederacy, it aroused fear among people in Ohio and Indiana as it was the furthest advancement of troops from the South in the war. Almost 35,000 Ohioans died in the conflict, and 30,000 were physically wounded. By the end of the Civil War, the Union's top three generals – Ulysses S. Grant, William Tecumseh Sherman, and Philip Sheridan – were all from Ohio.
Throughout much of the 19th century, industry was rapidly introduced to complement an existing agricultural economy. One of the first iron manufacturing plants opened near Youngstown in 1804 called Hopewell Furnace. By the mid-19th century, 48 blast furnaces were operating in the state, most in the southern portions of the state. Discovery of coal deposits aided the further development of the steel industry in the state, and by 1853 Cleveland was the third largest iron and steel producer in the country. The first Bessemer converter was purchased by the Cleveland Rolling Mill Company, which eventually became part of the U.S. Steel Corporation following the merger of Federal Steel Company and Carnegie Steel, the first billion-dollar American corporation. The first open-hearth furnace used for steel production was constructed by the Otis Steel Company in Cleveland, and by 1892, Ohio ranked as the 2nd-largest steel-producing state behind Pennsylvania. Republic Steel was founded in Youngstown in 1899 and was at one point the nation's third-largest producer. Armco, now AK Steel, was founded in Middletown also in 1899.
The state legislature officially adopted the flag of Ohio on May 9, 1902. Dayton natives Orville and Wilbur Wright made four brief flights at Kitty Hawk, North Carolina on December 17, 1903, inventing the first successful airplane. Ohio was hit by its greatest natural disaster in the Great Flood of 1913, resulting in at least 428 fatalities and hundreds of millions of dollars in property damage, particularly around the Great Miami River basin.
The National Football League was originally founded in Canton, Ohio in 1920 as the American Professional Football Conference. It included Ohio League teams in five Ohio cities (Akron, Canton, Cleveland, Columbus, and Dayton), although none of these teams still exist. The first official game occurred on October 3, 1920, when the Dayton Triangles beat the Columbus Panhandles 14-0 in Dayton. Canton would later be enshrined as the home of the Pro Football Hall of Fame in 1963.
During the 1930s, the Great Depression struck the state hard. By 1933, more than 40% of factory workers and 67% of construction workers were unemployed in Ohio. Approximately 50% of industrial workers in Cleveland and 80% in Toledo became unemployed, with the state unemployment rate reaching a high of 37.3%. American Jews watched the rise of Nazi Germany with apprehension. Cleveland residents Jerry Siegel and Joe Shuster created the Superman comic character in the spirit of the Jewish golem. Many of their comics portrayed Superman fighting and defeating the Nazis. Approximately 839,000 Ohioans served in the U.S. armed forces during World War II, of which over 23,000 died or were missing in action.
Artists, writers, musicians and actors developed in the state throughout the 20th century and often moved to other cities which were larger centers for their work. They included Zane Grey, Milton Caniff, George Bellows, Art Tatum, Roy Lichtenstein, and Roy Rogers. Alan Freed, who emerged from the swing dance culture in Cleveland, hosted the first live rock 'n roll concert in Cleveland in 1952. Famous filmmakers include Steven Spielberg, Chris Columbus and the original Warner Brothers, who set up their first movie theatre in Youngstown before that company later relocated to California. The state produced many popular musicians, including Dean Martin, Doris Day, The O'Jays, Marilyn Manson, Dave Grohl, Devo, Macy Gray and The Isley Brothers.
Two Ohio astronauts completed significant milestones in the space race in the 1960s: John Glenn becoming the first American to orbit the Earth, and Neil Armstrong becoming the first human to walk on the Moon. In 1967, Carl Stokes was elected mayor of Cleveland and became the first African American mayor of one of the nation's 10 most populous cities.
In 1970, an Ohio Army National Guard unit fired at students during an anti-war protest at Kent State University, killing four and wounding nine. The Guard had been called onto campus after several protests in and around campus had become violent, including a riot in downtown Kent and the burning of an ROTC building. The main cause of the protests was the United States' invasion of Cambodia during the Vietnam War.
Beginning in the 1980s, the state entered into international economic and resource cooperation treaties and organizations with other Midwestern states, as well as New York, Pennsylvania, Ontario, and Quebec, including the Great Lakes Charter, Great Lakes Compact, and the Council of Great Lakes Governors.
Ohio had become nicknamed the "fuel cell corridor" in being a contributing anchor for the region now called the "Green Belt," in reference to the growing renewable energy sector. Although the state experienced heavy manufacturing losses at the close of the 20th century and suffered from the Great Recession, it was rebounding by the second decade in being the country's 6th-fastest-growing economy through the first half of 2010.
Ohio's transition into the 21st century was symbolized by the Third Frontier program, spearheaded by governor Bob Taft around the start of the century. This built on the agricultural and industrial pillars of the economy, dubbed the first and second frontiers, by aiding the growth of advanced technology industries, the third frontier. The results of this initiative were considered widely successful, attracting 637 new high-tech companies to the state and 55,000 new jobs, with an average of salary of $65,000, while having a $6.6 billion economic impact with an investment return ratio of 9:1. In 2010 the state won the International Economic Development Council's Excellence in Economic Development Award, celebrated as a national model of success.
Many of the state's former industrial centers turned to new industries, including Akron as a center for polymer and biomedical research, Cincinnati as the state's largest mercantile hub, Columbus as a center for technological research and development, education, and insurance, Cleveland in regenerative medicine research and manufacturing, Dayton as an aerospace and defense hub, and Toledo as a national center for solar technology. Ohio was hit hard by the Great Recession and manufacturing employment losses entering the 2010s. The recession cost the state 376,500 jobs and it had 89,053 foreclosures in 2009, a record for the state. The median household income dropped 7% and the poverty rate ballooned to 13.5% by 2009. In 2015, Ohio gross domestic product was $608.1 billion, the seventh-largest economy among the 50 states. In 2015, Ohio's total GDP accounted for 3.4% of U.S. GDP and 0.8% of world GDP.
Ohio's geographic location has proven to be an asset for economic growth and expansion. Because Ohio links the Northeast to the Midwest, much cargo and business traffic passes through its borders along its well-developed highways. Ohio has the nation's 10th largest highway network and is within a one-day drive of 50% of North America's population and 70% of North America's manufacturing capacity. To the north, Ohio has 312 miles (502 km) of coastline with Lake Erie, which allows for numerous cargo ports such as Cleveland and Toledo. Ohio's southern border is defined by the Ohio River. Ohio's neighbors are Pennsylvania to the east, Michigan to the northwest, Lake Erie to the north, Indiana to the west, Kentucky on the south, and West Virginia on the southeast. Ohio's borders were defined by metes and bounds in the Enabling Act of 1802 as follows:
Ohio is bounded by the Ohio River, but nearly all of the river itself belongs to Kentucky and West Virginia. In 1980, the U.S. Supreme Court held that, based on the wording of the cessation of territory by Virginia (which at the time included what is now Kentucky and West Virginia), the boundary between Ohio and Kentucky (and, by implication, West Virginia) is the northern low-water mark of the river as it existed in 1792. Ohio has only that portion of the river between the river's 1792 low-water mark and the present high-water mark.
The border with Michigan has also changed, as a result of the Toledo War, to angle slightly northeast to the north shore of the mouth of the Maumee River.
Much of Ohio features glaciated till plains, with an exceptionally flat area in the northwest being known as the Great Black Swamp. This glaciated region in the northwest and central state is bordered to the east and southeast first by a belt known as the glaciated Allegheny Plateau, and then by another belt known as the unglaciated Allegheny Plateau. Most of Ohio is of low relief, but the unglaciated Allegheny Plateau features rugged hills and forests.
The rugged southeastern quadrant of Ohio, stretching in an outward bow-like arc along the Ohio River from the West Virginia Panhandle to the outskirts of Cincinnati, forms a distinct socio-economic unit. Geologically similar to parts of West Virginia and southwestern Pennsylvania, this area's coal mining legacy, dependence on small pockets of old manufacturing establishments, and distinctive regional dialect set this section off from the rest of the state. In 1965 the United States Congress passed the Appalachian Regional Development Act, an attempt to "address the persistent poverty and growing economic despair of the Appalachian Region". This act defines 29 Ohio counties as part of Appalachia. While 1/3 of Ohio's land mass is part of the federally defined Appalachian region, only 12.8% of Ohioans live there (1.476 million people.)
Significant rivers within the state include the Cuyahoga River, Great Miami River, Maumee River, Muskingum River, and Scioto River. The rivers in the northern part of the state drain into the northern Atlantic Ocean via Lake Erie and the St. Lawrence River, and the rivers in the southern part of the state drain into the Gulf of Mexico via the Ohio River and then the Mississippi.
The worst weather disaster in Ohio history occurred along the Great Miami River in 1913. Known as the Great Dayton Flood, the entire Miami River watershed flooded, including the downtown business district of Dayton. As a result, the Miami Conservancy District was created as the first major flood plain engineering project in Ohio and the United States.
Grand Lake St. Marys in the west-central part of the state was constructed as a supply of water for canals in the canal-building era of 1820–1850. This body of water, over 20 square miles (52 km), was the largest artificial lake in the world when completed in 1845. Ohio's canal-building projects were not the economic fiasco that similar efforts were in other states. Some cities, such as Dayton, owe their industrial emergence to location on canals, and as late as 1910 interior canals carried much of the bulk freight of the state.
The climate of Ohio is a humid continental climate (Köppen climate classification Dfa/Dfb) throughout most of the state, except in the extreme southern counties of Ohio's Bluegrass region section, which are located on the northern periphery of the humid subtropical climate (Cfa) and Upland South region of the United States. Summers are typically hot and humid throughout the state, while winters generally range from cool to cold. Precipitation in Ohio is moderate year-round. Severe weather is not uncommon in the state, although there are typically fewer tornado reports in Ohio than in states located in what is known as the Tornado Alley. Severe lake effect snowstorms are also not uncommon on the southeast shore of Lake Erie, which is located in an area designated as the Snowbelt.
Although predominantly not in a subtropical climate, some warmer-climate flora and fauna do reach well into Ohio. For instance, some trees with more southern ranges, such as the blackjack oak, Quercus marilandica, are found at their northernmost in Ohio just north of the Ohio River. Also evidencing this climatic transition from a subtropical to continental climate, several plants such as the Southern magnolia (Magnolia grandiflora), Albizia julibrissin (mimosa), Crape Myrtle, and even the occasional Needle Palm are hardy landscape materials regularly used as street, yard, and garden plantings in the Bluegrass region of Ohio; but these same plants will simply not thrive in much of the rest of the state. This interesting change may be observed while traveling through Ohio on Interstate 75 from Cincinnati to Toledo; the observant traveler of this diverse state may even catch a glimpse of Cincinnati's common wall lizard, one of the few examples of permanent "subtropical" fauna in Ohio.
The highest recorded temperature was 113 °F (45 °C), near Gallipolis on July 21, 1934. The lowest recorded temperature was −39 °F (−39 °C), at Milligan on February 10, 1899, during the Great Blizzard of 1899.
Although few have registered as noticeable to the average resident, more than 200 earthquakes with a magnitude of 2.0 or higher have occurred in Ohio since 1776. The Western Ohio Seismic Zone and a portion of the Southern Great Lakes Seismic Zone are located in the state, and numerous faults lie under the surface.
The most substantial known earthquake in Ohio history was the Anna (Shelby County) earthquake, which occurred on March 9, 1937. It was centered in western Ohio, and had a magnitude of 5.4, and was of intensity VIII.
Other significant earthquakes in Ohio include: one of magnitude 4.8 near Lima on September 19, 1884; one of magnitude 4.2 near Portsmouth on May 17, 1901; and one of 5.0 in LeRoy Township in Lake County on January 31, 1986, which continued to trigger 13 aftershocks of magnitude 0.5 to 2.4 for two months.
Notable Ohio earthquakes in the 21st century include one occurring on December 31, 2011, approximately 4 kilometers (2.5 mi) northwest of Youngstown, and one occurring on June 10, 2019, approximately 5 kilometers (3.1 mi) north-northwest of Eastlake under Lake Erie; both registered a 4.0 magnitude.
From just over 45,000 residents in 1800, Ohio's population grew faster than 10% per decade (except for the 1940 census) until the 1970 census, which recorded just over 10.65 million Ohioans. Growth then slowed for the next four decades. The United States Census Bureau counted 11,808,848 in the 2020 census, a 2.4% increase since the 2010 United States census. Ohio's population growth lags that of the entire United States, and whites are found in a greater density than the US average. As of 2000, Ohio's center of population is located in Morrow County, in the county seat of Mount Gilead. This is approximately 6,346 feet (1,934 m) south and west of Ohio's population center in 1990.
As of 2011, 27.6% of Ohio's children under the age of 1 belonged to minority groups.
6.2% of Ohio's population is under five years of age, 23.7 percent under 18 years of age, and 14.1 percent were 65 or older. Females made up approximately 51.2 percent of the population.
Note: Births in table do not add up because Hispanics are counted both by their ethnicity and by their race, giving a higher overall number.
In 2010, there were 469,700 foreign-born residents in Ohio, corresponding to 4.1% of the total population. Of these, 229,049 (2.0%) were naturalized US citizens and 240,699 (2.1%) were not. The largest groups were: Mexico (54,166), India (50,256), China (34,901), Germany (19,219), Philippines (16,410), United Kingdom (15,917), Canada (14,223), Russia (11,763), South Korea (11,307), and Ukraine (10,681). Though predominantly white, Ohio has large black populations in all major metropolitan areas throughout the state, Ohio has a significant Hispanic population made up of Mexicans in Toledo and Columbus, and Puerto Ricans in Cleveland and Columbus, and also has a significant and diverse Asian population in Columbus.
The largest ancestry groups (which the census defines as not including racial terms) in the state are:
Ancestries claimed by less than 1% of the population include Sub-Saharan African, Puerto Rican, Swiss, Swedish, Arab, Greek, Norwegian, Romanian, Austrian, Lithuanian, Finnish, West Indian, Portuguese and Slovene.
About 6.7% of the population age 5 years and older reported speaking a language other than English, with 2.2% of the population speaking Spanish, 2.6% speaking other Indo-European languages, 1.1% speaking Asian and Austronesian languages, and 0.8% speaking other languages. Numerically: 10,100,586 spoke English, 239,229 Spanish, 55,970 German, 38,990 Chinese, 33,125 Arabic, and 32,019 French. In addition 59,881 spoke a Slavic language and 42,673 spoke another West Germanic language according to the 2010 census. Ohio also had the nation's largest population of Slovene speakers, second largest of Slovak speakers, second largest of Pennsylvania Dutch (German) speakers, and the third largest of Serbian speakers.
According to a Pew Forum poll, as of 2014, 73% of Ohioans identified as Christian. Specifically, 29% of Ohio's population identified as Evangelical Protestant, 17% as Mainline Protestant, 7% as Historically Black Protestant, and 18% as Catholic. 22% of the population is unaffiliated with any religious body. Small minorities of Jews (1%), Jehovah's Witnesses (1%), Muslims (1%), Hindus (<1%), Buddhists (1%), Mormons (1%), and other faiths (1-1.5%) exist.
According to the Association of Religion Data Archives (ARDA), in 2010 the largest denominations by adherents were the Catholic Church with 1,992,567; the United Methodist Church with 496,232; the Evangelical Lutheran Church in America with 223,253, the Southern Baptist Convention with 171,000, the Christian Churches and Churches of Christ with 141,311, the United Church of Christ with 118,000, and the Presbyterian Church (USA) with 110,000. With about 80,000 adherents in 2020, Ohio has the second largest Amish population of all U.S. states, only behind neighboring Pennsylvania.
According to the same data, a majority of Ohioans, 56%, feel religion is "very important", 25% that it is "somewhat important", and 19% that religion is "not too important/not important at all". 38% of Ohioans indicate that they attend religious services at least once weekly, 32% occasionally, and 30% seldom or never.