"United States Census, 1900," index and images, FamilySearch (https://familysearch.org/pal:/MM9.1.1/MS78-4F7 : accessed 19 Oct 2013), John Harekamp in household of John Harekamp, ED 1130 Precinct 56 Calumet Township Chicago city Ward 34, Cook, Illinois, United States; citing sheet 5B, family 81, NARA microfilm publication T623, FHL microfilm 1240291.