The following histories of Illinois Civil War regiments and units originate from the first eight volumes of the nine volume publication, Report of the Adjutant General of the State of Illinois (1900-1902). The histories, some written shortly after the war’s end, are the work of numerous authors throughout the intervening years. The 1886 version of the Adjutant General’s Report included regimental histories compiled by that office which had not previously been published. The final 1900-1902 republication of the report incorporated revisions and corrections to the histories.