My Great Great Grandfather Nathan W.J. Curtis Brown joined the US Army 9 AUG 1862 as a Private  in  Company H, 89th Regiment, Illinois Infantry.  He was discharged 6 Mar 1863 for chronic diarrhea and being emaciated.   He joined Co E, 17th Regiment , Illinois Cavalry as recruit 12 Feb 1864 and was discharged 23 Nov 1865 as a Corporal.