Hamilton County
County
Hamilton County Courthouse
Flag Seal Logo
Location within the U.S. state of Ohio
Ohio's location within the U.S.
Coordinates: 39°12′N 84°32′W / 39.2°N 84.54°W / 39.2; -84.54
Country	United States
State	Ohio
Founded	January 2, 1790[1]
Named for	Alexander Hamilton
Seat	Cincinnati
Largest city	Cincinnati
Area
• Total	413 sq mi (1,070 km2)
• Land	406 sq mi (1,050 km2)
• Water	6.7 sq mi (17 km2)  1.6%
Population  (2020)
• Total	830,639
• Estimate  (2023)	827,058
• Density	2,000/sq mi (780/km2)
Time zone	UTC−5 (Eastern)
• Summer (DST)	UTC−4 (EDT)
Congressional districts	1st, 8th
Website	hamilton-co.org

Hamilton County is located in the southwestern corner of the U.S. state of Ohio. As of the 2020 census, the population was 830,639,^[2] making it the third-most populous county in Ohio. The county seat and most populous city is Cincinnati.^[3] The county is named for the first Secretary of the Treasury, Alexander Hamilton.^[4] Hamilton County is part of the Cincinnati-Middletown, OH-KY-IN Metropolitan Statistical Area.

The southern portion of Hamilton County was originally owned and surveyed by John Cleves Symmes, and the region was a part of the Symmes Purchase. The first settlers rafted down the Ohio River in 1788 following the American Revolutionary War. They established the towns of Losantiville (later Cincinnati), North Bend, and Columbia.

Hamilton County was organized in 1790 by order of Arthur St. Clair, governor of the Northwest Territory, as the second county in the Northwest Territory. Cincinnati was named as the seat. Residents named the county in honor of Alexander Hamilton, who was the first Secretary of the Treasury of the United States and a founder of the Federalist Party. Its original boundaries were those defined for the Symmes purchase contract in 1788:^[5] the Ohio River in the South, Great Miami River to the west, the Lesser Miami River to the east, and the Cuyahoga River to the North. Its area then included about one-eighth of Ohio and had about 2,000 inhabitants (not including the remaining Native Americans).

The county was greatly expanded in 1792 to include what is today the lower peninsula of Michigan. Since 1796, other counties were created from Hamilton, reducing the county to its present size. The county was the location of much of the Northwest Indian War before and after its organization.

The United States forcibly removed most of the Shawnee and other Indian peoples to move to locations west of the Mississippi River in the 1820s.

Rapid growth occurred during the 1830s and 1840s as the area attracted many German and Irish immigrants, especially after the Great Famine in Ireland and the revolutions in Germany in 1848.

During the Civil War, Morgan's Raid (a Confederate cavalry campaign from Kentucky) passed through the northern part of the county during the summer of 1863.

The Sharonville Engineer Depot was constructed by the United States Army in northern Hamilton County in 1942, and continued to be used by the General Services Administration and then the Defense Logistics Agency after 1949. It is currently mostly redeveloped for industrial purposes.

According to the U.S. Census Bureau, the county has a total area of 413 square miles (1,070 km²), of which 406 square miles (1,050 km²) is land and 6.7 square miles (17 km²) (1.6%) is water.^[6]

• Franklin County, Indiana (northwest)
• Dearborn County, Indiana (west)
• Butler County (north)
• Warren County (northeast)
• Clermont County (east)
• Campbell County, Kentucky (southeast)
• Kenton County, Kentucky (south)
• Boone County, Kentucky (southwest)

The county lies in a region of gentle hills formed by the slopes of the Ohio River valley and its tributaries. The Great Miami River, the Little Miami River, and the Mill Creek also contribute to this system of hillsides and valleys. No naturally occurring lakes exist, but three major humanmade lakes are part of the Great Parks of Hamilton County.^[7] The largest lake by far is Winton Woods Lake, covering 188 surface acres, followed by Miami Whitewater Lake, covering 85 surface acres, and Sharon Lake, covering 36 surface acres.

The county boundaries include the lowest point in Ohio, in Miami Township, where the Ohio River flows out of Ohio and into Indiana. This is the upper pool elevation behind the Markland Dam, 455 feet (139 m) above sea level.^[8]

The highest land elevation in Hamilton County is the Rumpke Sanitary Landfill at 1,045 feet (319 m) above sea level in Colerain Township.

As of the census of 2020, there were 830,639 people living in the county, for a population density of 2,045.91 people per square mile (791.08/km²). There were 379,015 housing units. The racial makeup of the county was 63.3% White, 25.2% Black or African American, 0.3% Native American, 3.0% Asian, 0.1% Pacific Islander, 2.4% from some other race, and 5.7% from two or more races. 4.4% of the population were Hispanic or Latino of any race.^[15]

There were 355,784 households, out of which 26.3% had children under the age of 18 living with them, 39.3% were married couples living together, 20.5% had a male householder with no spouse present, and 32.5% had a female householder with no spouse present. 34.3% of all households were made up of individuals, and 12.0% were someone living alone who was 65 years of age or older. The average household size was 2.26, and the average family size was 2.96.^[15]

22.6% of the county's population were under the age of 18, 60.5% were 18 to 64, and 16.9% were 65 years of age or older. The median age was 37.0. For every 100 females, there were 94.7 males.^[15]

According to the U.S. Census American Community Survey, for the period 2016-2020 the estimated median annual income for a household in the county was $66,878, and the median income for a family was $92,480. About 15.3% of the population were living below the poverty line, including 17.6% of those under age 18 and 10.8% of those age 65 or over. About 64.1% of the population were employed, and 41.8% had a bachelor's degree or higher.^[15]

As of the 2010 census, there were 802,374 people, 333,945 households, and 197,571 families living in the county.^[16] The population density was 1,976.7 inhabitants per square mile (763.2/km²). There were 377,364 housing units at an average density of 929.7 per square mile (359.0/km²).^[17] The racial makeup of the county was 68.8% white, 25.7% black or African American, 2.0% Asian, 0.2% American Indian, 0.1% Pacific islander, 1.1% from other races, and 2.1% from two or more races. Those of Hispanic or Latino origin made up 2.6% of the population.^[16] In terms of ancestry, 31.0% were German, 14.7% were Irish, 7.7% were English, and 6.6% were American.^[18]

Of the 333,945 households, 29.7% had children under the age of 18 living with them, 39.4% were married couples living together, 15.4% had a female householder with no husband present, 40.8% were non-families, and 33.9% of all households were made up of individuals. The average household size was 2.34 and the average family size was 3.04. The median age was 37.1 years.^[16]

The median income for a household in the county was $48,234 and the median income for a family was $64,683. Males had a median income of $48,344 versus $37,310 for females. The per capita income for the county was $28,799. About 11.1% of families and 15.4% of the population were below the poverty line, including 22.9% of those under age 18 and 9.0% of those age 65 or over.^[19]

As of the 2000 census, there were 845,303 people, 346,790 households, and 212,582 families living in the county. The population density was 2,075 inhabitants per square mile (801/km²). There were 373,393 housing units at an average density of 917 per square mile (354/km²). The racial makeup of the county was 69.2% White, 26.0% Black or African American, 0.1% Native American, 2.3% Asian, 0.01% Pacific Islander, 0.51% from other races, and 2.2% from two or more races. 2.8% of the population were Hispanic or Latino of any race.

There were 346,790 households, out of which 30.20% had children under the age of 18 living with them, 43.40% were married couples living together, 14.30% had a female householder with no husband present, and 38.70% were non-families. 32.90% of all households were made up of individuals, and 10.60% had someone living alone who was 65 years of age or older. The average household size was 2.38 and the average family size was 3.07.

In the county, the population was spread out, with 25.80% under the age of 18, 9.60% from 18 to 24, 29.70% from 25 to 44, 21.50% from 45 to 64, and 13.50% who were 65 years of age or older. The median age was 36 years. For every 100 females there were 91.10 males. For every 100 females age 18 and over, there were 86.80 males.

The median income for a household in the county was $40,964, and the median income for a family was $53,449. Males had a median income of $39,842 versus $28,550 for females. The per capita income for the county was $24,053. About 8.80% of families and 11.80% of the population were below the poverty line, including 16.20% of those under age 18 and 8.70% of those age 65 or over.

The county's highest population was recorded in the 1970 U.S. Census. Since then, the county has lost population at an average rate of three percent per decade. Although Hamilton County is experiencing a decline in birth rates and has higher death rates in older age groups (cohorts), out-migration of residents is the key factor in population loss. In the last decade, this population loss has been reversed, and it is estimated that both Hamilton County and the City of Cincinnati have grown their populations.^[20] The Cincinnati Metropolitan Statistical Area, over the last three decades has seen a 19 percent increase in population. Much of the region's growth has been through movement of Cincinnati and Hamilton County residents into neighboring counties.^[20]

As of 2020, the members of the Hamilton Board of County Commissioners are Denise Driehaus, Stephanie Summerow Dumas, and Alicia Reece.^[21]

Since 1963, the Board has employed an administrator to run the day-to-day operations of the county; the current administrator is Jeffrey Aluotto.^[22] Other elected officers include Dusty Rhodes (Auditor), Joe Deters (Prosecutor), Charmaine McGuffey (Sheriff), Eric Beck (Engineer), Scott Crowley (Recorder), Jill Schiller (Treasurer), and Lakshmi Sammarco (Coroner).^[22]

As of 2021, the elected Common Pleas Court include: Judge Jody Luebbers, Judge Lisa Allen, Judge Jennifer Branch, Judge Wende Cross, Judge Leslie Ghiz, Judge Robert Goering, Judge Tom Heekin, Judge Christian Jenkins, Judge Charles Kubicki, Judge Melba Marsh, Judge Terry Nestor, Judge Robert Ruehlman, Judge Nicole Sanders, Judge Megan Shanahan, Judge Alan Triggs, and Judge Christopher Wagner.^[23]

Hamilton County was historically rather conservative for an urban county. It long favored Republican candidates in national elections, but has trended Democratic in recent years. In 2008, Barack Obama was the first Democratic presidential candidate to win the county since 1964, and only the second since 1936. The county continued to lean Democratic, voting for Obama again in 2012 and for Democratic candidate Hillary Clinton in 2016. In fact, it was one of the few counties in Ohio to swing toward the Democrats in 2016 even as the state as a whole swung toward the Republicans.

In other state elections, the county also tended to favor Republican candidates. Richard Cordray in his failed 2018 bid was the first Democrat to win the county in a gubernatorial election since Dick Celeste in 1982, and only the second since Michael DiSalle in 1958.^[24][25] In Senate elections, the county also tended to back Republicans, but has been won by Frank Lausche in 1962, John Glenn in all four of his elections and Howard Metzenbaum and Sherrod Brown in two out of three elections for both (1982 and 1988, and 2012 and 2018).^[26] In the 2006 Ohio elections, both Ted Strickland and Sherrod Brown lost the county by less than 2,000 votes while winning statewide by 24 and 12 points, respectively.

With the election of Democrat Stephanie Summerow Dumas in 2018 midterm elections, the Hamilton County Board of Commissioners was entirely Democratic for the first time ever.^[27] Democrats had previously regained majority control of the Board of Commissioners in 2016 with the election of Denise Driehaus. In 2019, longtime Democratic Commissioner Todd Portune announced his resignation from the Board due to health problems. Portune's Chief of Staff, Victoria Parks, was appointed to serve the remainder of his term (through the November 2020 general election). With Parks' appointment, the Board of Commissioners became for the first time all-female and majority Black.^[28] In the November 2020 election, Democrat Alicia Reece was elected to fill Parks' seat, thereby retaining the Board's status as all-female and majority Black.^[21]

Historically, due to its tight races and its position in the swing state of Ohio, Hamilton County was regarded as a crucial county to win in presidential elections. In 2012, The Washington Post named Hamilton as one of the seven most important counties in the country for that year's election.^[29] Time characterized Hamilton County's political scene as "a battle between conservative suburbs and a Democratic urban center, though Cincinnati is one of the most conservative metro areas in the Midwest."^[30] Those characterizations became less true in recent years. While many of Cincinnati's western suburbs, like Green and Delhi Townships, continue to strongly support Republican candidates, the city itself and most of its northern suburbs vote strongly Democratic.

Public elementary and secondary education is provided by 23 school districts:^[33]

In 2016, Cincinnati Public Schools had 35,000 students, 63% of which were African-American.^[34] The county also has a vocational school district, the Great Oaks Institute of Technology and Career Development. Parochial schools of various denominations add to this base. Among these the Roman Catholic Archdiocese of Cincinnati maintains a system of 108 elementary and 22 secondary schools, the ninth largest private school system in the United States.

Interstate 71, Interstate 74, Interstate 75, Interstate 471, and Interstate 275 serve the county. The Norwood Lateral and Ronald Reagan Cross County Highway are also prominent east–west thoroughfares in the county.

CSX Transportation, Norfolk Southern, RailAmerica, and Amtrak.^[35]

The county, in cooperation with the City of Cincinnati, operates the Public Library of Cincinnati and Hamilton County system with a main library and 41 branches. Major sports teams are listed under the communities in which they are located, primarily Cincinnati. The Great Parks of Hamilton County district resides within Hamilton County and maintains a series of preserves and educational facilities. Three of the largest parks within the system are Miami Whitewater Forest, Winton Woods, and Sharon Woods. The Hamilton County Fair is the oldest county fair in Ohio.

The following list includes townships that have existed within present-day Hamilton County, including those that no longer exist or remain only as paper townships. It does not include townships that became part of Butler, Warren, Clermont, Montgomery, and other counties.

• Colerain Heights
• Mount Saint Joseph

• National Register of Historic Places listings in Hamilton County, Ohio

• County website
• Hamilton County Park District
• Hamilton County Board of Mental Retardation & Developmental Disabilities
• Hamilton County, Ohio History and Genealogy
• Flag of Hamilton County: crwflags.com and ihiochannel.org

39°12′N 84°32′W / 39.20°N 84.54°W / 39.20; -84.54