61455 -- U.S. ZIP code Municipality (1990): MACOMB, Illinois All ZIPs for this municipality (1990): 61455 Population (2000): 21659 Housing Units (2000): 8371 Land area (2000): 170.578616 sq. miles (441.796568 sq. km) Water area (2000): 0.462467 sq. miles (1.197785 sq. km) Total area (2000): 171.041083 sq. miles (442.994353 sq. km) Located within: Illinois (IL) Location: 40.456986 N, 90.668107 W