1. Rock Island, Rock Island County, Illinois, Jany. 1892 Maps University Of Illinois Urbana Champaign Public content 1892. Sanborn Map Company. Scale 1:600. 50 ft. to 1 in. Sheet 1 includes symbol key, index, and index map. Partial cadastral map. Fire insurance map hand colored to show buil... Sanborn-Perris Map Co.