For those looking for Hancock County, Illinois books on Archive.org:
History of Hancock County, Illinois, together with an outline history of the State, and a digest of State laws - Gregg, Thomas, b. 1808. cn16Keywords: Hancock County (Ill.) -- History; Hancock County (Ill.) -- Biography
Portrait and biographical record of Hancock, McDonough and Henderson counties, Illinois : containing biographical sketches of prominent and representative citizens of the countyKeywords: Hancock County (Ill.) -- Biography; McDonough County (Ill.) -- Biography; Henderson County (Ill.) -- Biography
Biographical review of Hancock County, Illinois : containing biographical and genealogical sketches of many of the prominent citizens of to-day and also of the past - Hobart Publishing Company, ChicagoKeywords: Hancock County (Ill.) -- Biography; Hancock County (Ill.) -- Genealogy
Biographical review of Hancock County, Illinois : containing biographical and genealogical sketches of many of the prominent citizens of to-day and also of the pastKeywords: Hancock County (Ill.) -- Biography; Hancock County (Ill.) -- Genealogy
American aerial county history series : (Volume 16 (HANCOCK)) - Drury, John, 1898-Keywords: Farms -- Illinois; Illinois -- Pictorial works; Illinois -- History