Tom--that's interesting. Maybe part of them were in the barracks. I based my comment on the following:
Private Pickens from the 5th Alabama (same company as tucker) noted that the troops finally halted just outside of town near "a large orchard." See his entry for June 27 in Hubbs, Voices from Conpany D., p. 181 for a more detailed account of their location, which mentions a location about 2 miles from town on Baltimore turnpilke. According to another Alabamian, they set up camp "on the roadside of the Baltimore Pike, about one mile from Carlisle, where we now are, doing picket-duty, and living on the fat of the land." That is from "Third Alabama Infantry, Letter from Pennsylvania," June 28, 1863, Mobile Advertiser and Register, July 20, 1863