Formed 10 Jan 1820, 434 square miles
Parent counties: Franklin, Madison, Logan, Delaware
Evolution of county from date of formation until it assumed its final form
1 Apr 1820: Erected and organized
Union County has had two county seats. The first, lasting only one year, was in Milford Center in 1820. The following year the county seat moved to Marysville.
Federal Population schedules extant from 1820-1940. (1890 missing)
1820 Manufacturers; 1850 Agricultural; 1850 Industry; 1850 Mortality; 1860 Industry; 1860 Mortality; 1870 Agricultural; 1870 Industry; 1880 Agricultural; 1880 Industry
Allen, Claibourne, Darby, Dover, Jackson, Jerome, Leesburg, Liberty, Millcreek, Paris, Taylor, Union, Washington, and York.
Jana Broglin, OGSF