Statistics for occurrence #1 of “Illinois” in chapter 9 of The Photographic History of The Civil War: in ten volumes, Thousands of Scenes Photographed 1861-65, with Text by many Special Authorities, Volume 10: The Armies and the Leaders.:

...de-camp, and Captain John A. Lightfoot, assistant adjutant-general, on duty at the department headquarters. On June 26, 1866, a call had been issued for a convention, to be held at Springfield, Illinois , July 12, 1866. The convention was held on this date and the Department of Illinois organized, General John M. Palmer being elected department commander. Doctor Stephenson was recognized, however...
Max. Freq. Min. Freq.
Entity Corpus Doc Corpus Doc  
Illinois (Illinois, United States) 6,200 40 0 0 0 user votes
Illinois (New Mexico, United States) 4 0 0 0 0 user votes
Illinois (Oregon, United States) 2 0 0 0 0 user votes
Illinois (Colorado, United States) 0 0 0 0 0 user votes
Illinois (Illinois, United States) 0 0 0 0 0 user votes
Illinois (New Mexico, United States) 0 0 0 0 0 user votes

† This entity has been selected by the automated classifier as the most likely match in this context. It may or may not be the correct match.