There were five corps in the Union Army designated as II Corps (Second Army Corps) during the American Civil War. These formations were the Army of the Cumberland II Corps commanded by Thomas L. Crittenden from October 24, 1862 to November 5, 1862, later renumbered XX Corps; the Army of the Mississippi II corps led by William T. Sherman from January 4, 1863 to January 12, 1863, renumbered XV Corps; Army of the Ohio II Corps commanded by Thomas L.