61489 -- U.S. ZIP code Municipality (1990): WILLIAMSFIELD, Illinois All ZIPs for this municipality (1990): 61489 Population (2000): 999 Housing Units (2000): 403 Land area (2000): 43.471279 sq. miles (112.590092 sq. km) Water area (2000): 0.071404 sq. miles (0.184936 sq. km) Total area (2000): 43.542683 sq. miles (112.775028 sq. km) Located within: Illinois (IL) Location: 40.929497 N, 90.018880 W