If you're interested in Missouri Confederates, you should know that The Compendium of the Confederate Armies: Kentucky, Maryland, Missouri, and the Indian Units by Stewart Sifakis is back in print. Sifakis' Compendium is the counterpart of Frederick Dyer's Compendium of the Union Armies:
NOTE 1: All other books in the Confederate Compendium are also available from the same source.
NOTE 2: You may also be interested in my book, The Missouri State Guard: a Selected, Annotated Unit Bibliography:
NOTE 3: Click on a book title to see an 11-page preview of that book!