The Collier books are excellent, especially for the time they were written nearly 40 years ago. I find a few differences from time to time as I find new sources or research for myself here and there, but they've done their job of getting folks interested in these units.

I loved the Willis book, as a good overall history of the western theater, and especially the use of observations of folks who were there at the time. If I recall rightly, the footnotes were a last-minute add-on, but they greatly magnify the value of the book by pointing to original references.

I started awhile back collecting campaign histories of most of the western battles, and this has helped a lot in figuring out the details. Larry Daniel, Nathaniel Cheairs Hughes Jr., and Peter Cozzens have done excellent work, and in the most part you can take these books out to the field with you and put yourself in the place of a particular unit. We've used Bill Shea's book on Pea Ridge to good effect this way, hiking out to some obscure corner of the park and then pulling out and reading the appropriate parts. There's a new version out now that covers Prairie Grove as well; I brought it back from the reenactment the first of this month, and have really enjoyed it.

Doyle:
Have you read Peter Cozzens' book on Corinth, THE DARKEST DAYS OF THE WAR? Good coverage, and excellent maps...

Tom