Camp Lyon was the site where Illinois volunteer soldiers of the Civil War were encamped from May 1861 to June 1864. The regiments and units encamped there included the 17th Infantry, beginning May 24, 1861, under Colonels L.F. Ross and A.S. Norton; the Peoria Battery, beginning May 26, 1861, under Captains P. Davidson, H. Borries, and W.W. Campbell; the 47th Infantry, beginning August 16, 1861, under Colonels J. Brymer, W.A. Thrush, J.M. Crommell, and J.D. McClure; the 11th Cavalry, beginning December 20, 1861, under Colonels R.G. Ingersoll, L.H. Kerr, and O. Funk; the 86th Infantry, beginning August 27, 1862, under Colonels D.D. Irons and A.L. Fahnestock; the 12th Infantry, in September 1862, under Colonel T.J. Henderson; the 14th Cavalry, in December 1862, under Colonels H. Capron and F.M. Davidson; and the 139th Infantry, beginning June 1, 1864, under Colonel P. Davidson.