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Ohio Counties

There is eighty-eight counties in the state of Ohio. Washington County the oldest in the state established on July 27, 1788. Noble County was formed on March 11, 1851 from portions of Guernsey, Morgan, Monroe and Washington counties. It was the last county to be formed in Ohio and, therefore, represents the youngest county in the state.

Trumbull County, Ohio

Trumbull County Education, Geography, and HistoryTrumbull County, Ohio Courthouse

Trumbull County is a county located in the state of Ohio. Based on the 2010 census, the population was 210,312. Its county seat is Warren.

Trumbull County is part of the Youngstown-Warren-Boardman, OH-PA Metropolitan Statistical Area.

Etymology - Origin of Trumbull County Name

The county was named in honor of Connecticut Governor Jonathan Trumbull.


County QuickFacts: CensusBureau Quick Facts

Trumbull County History

On July 10, 1800, the government of the Northwest Territory authorized the creation of Trumbull County. It originally was a portion of the Connecticut Western Reserve. The county was named in honor of Connecticut Governor Jonathan Trumbull.

Trumbull County is located in northeastern Ohio and covers 616 square miles. The county's eastern border helps form the boundary between Ohio and Pennsylvania. The county's population declined by 1.2 percent between 1990 and 2000 to a total of 225,116 residents. Warren is the county seat and the largest city in the county, with 46,832 residents in 2000. Trumbull County averages over 365 residents per square mile.

Trumbull County is overwhelmingly rural, with only four percent of the county's land area classified as urban. Most residents work in manufacturing, sales, or service positions. Farming ranks a distant fifth. Historically, steel production was a major industry in the county because of the large deposits of coal and iron ore in surrounding counties. Trumbull County's average income was 25,022 dollars per person in 1999, with 11.2 percent of the population living in poverty.

Most voters in Trumbull County claim to be independents.

United States President William McKinley, Jr., was born in the Trumbull County village of Niles. Trumbull County also was the birthplace of Clarence Darrow, a prominent American attorney during the early twentieth century

Trumbull County, Ohio History Central, July 24, 2008,

Geography: Land and Water

As reported by the Census Bureau, the county has a total area of 637 square miles (1,650 km2), of which 618 square miles (1,600 km2) is land and 18 square miles (47 km2) (2.9%) is water. It is approximately a square with sides of 25 miles; it is the only square county in Ohio.

Neighboring Counties

Bordering counties are as follows:

  • Ashtabula County (north)
  • Crawford County, Pennsylvania (northeast)
  • Mercer County, Pennsylvania (east)
  • Mahoning County (south)
  • Portage County (southwest)
  • Geauga County (northwest)


Kent State University Trumbull is a regional campus of Kent State University, offering several associate degrees and a few bachelor's degrees.

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