Fort Belvoir, Virginia, United States [CDP]; population was 8,590 in 1990; housing units was 2,106 in 1990; location is 38°43'N 77°9'W; land area is 7.90 square miles (5,058 acres); water area is 0.01 square miles (4 acres); FIPS code is 29008 [SourceCBP]