I think 85 is just what you're looking for. 240 is a pretty detailed study of Louisiana in the war, including battles. 267 is probably the most detailed study of Vicksburg ever written. 330 has a lot of information on the Battle of Westport that you won't find in other accounts, since the author seems to have had access to battle reports of all the Kansas Militia units (these aren't in the ORs). 395 is a pretty lightweight study, not to put it down.
Clark

Craig,
Clark is certainly right about the Frazier book Cottonclads! Frazier is a very good writer and historian but most of the books from that particular series lack serious depth. Other books in the Camp Pope catalog, like Ed Cotham's books on Galveston and Sabine Pass give you a much better picture (battle detail, OBs) about the war on the Texas coast. You might want to try Townsend's book "The Yankee Invasion of Texas" as well. All of these can be found here.

Drew