The U.S. state of Ohio comprises 88 counties. Nine of them existed at the time of the Ohio Constitutional Convention in 1802. A tenth county, Wayne, was established on August 15, 1796, and encompassed roughly the present state of Michigan. During the Convention, the county was opposed to statehood, and was not only left out of the Convention, but dissolved; the current Wayne County is in northeastern Ohio, considerably distant from the area that was the original Wayne County. The Ohio Constitution allows counties to set up a charter government as many cities and villages do, but only Summit and Cuyahoga counties have done so, the latter having been approved by voters in November 2009. Counties do not possess home rule powers and can do only what has been expressly authorized by the Ohio General Assembly. Ohio law defines a structure for county government, although each county may choose to define its own. Summit County and Cuyahoga County have chosen an alternate structure, while all of the other counties use the default structure. The elected county officials include three commissioners, a sheriff ; prosecutor ; coroner, engineer, auditor, treasurer and clerk of courts. Population figures are based on the 2010 United States Census. The population of Ohio was 11,536,504 at that time, an increase of 1.6% from 2000. The average population of Ohio's counties was 131,096; Cuyahoga County was the most populous and Vinton County was the least. The average land area is. The largest county by area is Ashtabula County at, and its neighbor, Lake County, is the smallest at. The total area of the state is. The Federal Information Processing Standard is used by the U.S. government to uniquely identify counties, and is provided for each entry. These codes link to the United States Census Bureau's "quick facts" for each county. Ohio's FIPS code of 39 is used to distinguish from counties in other states. For example, Adams County's unique nationwide identifier is 39001. However, the Bureau of Motor Vehicles and Department of Transportation instead identify counties by consecutive numbers and three-letter abbreviations, respectively.
