Princeton, IL -- U.S. city in Illinois Population (2000): 7501 Housing Units (2000): 3513 Land area (2000): 6.729817 sq. miles (17.430146 sq. km) Water area (2000): 0.000000 sq. miles (0.000000 sq. km) Total area (2000): 6.729817 sq. miles (17.430146 sq. km) FIPS code: 61899 Located within: Illinois (IL), FIPS 17 Location: 41.378481 N, 89.466924 W ZIP Codes (1990): 61356 Note: some ZIP codes may be omitted esp. for suburbs. Headwords: Princeton, IL Princeton