Union -- U.S. County in Kentucky Population (2000): 15637 Housing Units (2000): 6234 Land area (2000): 345.097663 sq. miles (893.798807 sq. km) Water area (2000): 18.330144 sq. miles (47.474852 sq. km) Total area (2000): 363.427807 sq. miles (941.273659 sq. km) Located within: Kentucky (KY), FIPS 21 Location: 37.645700 N, 87.931029 W Headwords: Union Union, KY Union County Union County, KY