Union -- U.S. County in Mississippi Population (2000): 25362 Housing Units (2000): 10693 Land area (2000): 415.430555 sq. miles (1075.960153 sq. km) Water area (2000): 1.442909 sq. miles (3.737118 sq. km) Total area (2000): 416.873464 sq. miles (1079.697271 sq. km) Located within: Mississippi (MS), FIPS 28 Location: 34.489085 N, 88.999738 W Headwords: Union Union, MS Union County Union County, MS