Conscripted soldiers were sent to the nearest camp of instruction. There were two in each of the larger states. Conscripts were assigned to infantry regiments after an indefinite stay at camp of instruction. Usually they were sent in a large groups to the camp of a Georgia brigade and distributed according to need.
If the James H. Cassady in Olmstead's 1st Georgia Regiment really came from Chatham County GA, he should appear on the 1860 census for that county.