Union, MO -- U.S. city in Missouri Population (2000): 7757 Housing Units (2000): 3133 Land area (2000): 8.080852 sq. miles (20.929310 sq. km) Water area (2000): 0.000000 sq. miles (0.000000 sq. km) Total area (2000): 8.080852 sq. miles (20.929310 sq. km) FIPS code: 74626 Located within: Missouri (MO), FIPS 29 Location: 38.446684 N, 91.006070 W ZIP Codes (1990): 63084 Note: some ZIP codes may be omitted esp. for suburbs. Headwords: Union, MO Union