Your kin was lucky as to the time he was at Camp Douglas and the fact he was wounded. Could you give his name?Originally a training camp with around five thousand men early on.It held its first prisoners from Ft. Donelson in Feb.1862.In the next several months many of those would of been exchanged.I believe the exchange point was Vicksburg.Camp Douglas recieved around 8,762 prisoners from Island #10 and Shiloh.It was built to hold 8000-9000 men.The conditions were not good.Management poor but was returned to a training camp in the fall of 1862.My GGuncles 127IL.Inf.were trained there.I say he was lucky as he missed winter,I've seen 15'below zero,being wounded the hospitol might of offered better care then standard inmates. The conditions got worse after July of 1863 with the collasp of the Dix-Hill Cartel few prisonors were exchanged and overcrowding became a problem.Large numbers of men in one place was something new and the outbreak of smallpox killed many.Then in 1864 Federal policies changed and they were treated worse,conditions were worse.Giving Camp Douglas the reputation you hear today.On my mother's side my GGGGrandfather Pvt. Daniel Riordan 6LA.Inf. Co F was at Elmira it is a toss up of which was worse.
I might find further info if I knew his name and Regiment.Hope this gives you some info.