yes, in the South's case, they had trouble feeding and clothing their own troops, let alone taking care of prisoners. That was the defence raised by capt. Wirz, the commander of andersonville:
http://en.wikipedia.org/wiki/Anderso...ite#Conditions
In the early part of the war, the Union and the rebels exchanged prisoners, which lessened the problem, but the Union stopped that once they figured out the CSA was running out of men.
In the North's case, there was less of an excuse for the poor conditions, but it appears to be more a case of incompetence and corruption rather voluntary mistreatment.
Let's not forget that the diet of serving Union soldiers was very poor, usually moldy bread/biscuits, dried/salted meat and coffee and they were the lucky ones...
