Being busy in school at the time, Stanley McGowen's Horse Sweat and Powder Smoke: The First Texas Cavalry in the Civil War (TAMU, 1999) slipped by me when it first appeared. A decent number of modern Texas cavalry unit studies have been published before and since [many of the earlier ones quite pricey], but this one is my favorite to date. Even 15 years later, it's not too late to get a brand new, shrinkwrapped copy, either, as the book remains in print and widely available.
The study does not include a roster and the demographic analysis of the men that served in the ranks is fairly minimal by today's standards. The large number of German-Americans in the regiment will interest many readers more familiar with stories surrounding the pro-Union element among German-Texan citizenry. McGowen provides detailed mini-biographies of their officers (including that of the talented professional soldier that would eventually lead the regiment, Augustus Buchel) but unfortunately wasn't able to uncover much common soldier source material documenting the source of their Confederate loyalties and what they thought about their unionist neighbors
McGowen does devote a great deal of space in the book to the difficulties of frontier military service in the Confederacy, including how the Texans dealt with scarcities in food, supplies, weapons, horses, equipment, and medical services in camp and on campaign. Horse Sweat and Powder Smoke really is a noteworthy original when it comes to Trans-Mississippi regimental histories. From Indian fighting to border security to suppressing armed internal dissent to defending coastal and overland routes from Union invasion, the variety of roles performed by the men of the First Texas Cavalry almost perfectly encapsulates the entire range of Civil War Texas military experiences.