Another Confederate cavalry raid impends. You hear the snort of an impatient horse, the leathery squeaking of saddles, the low-voiced commands of officers, the muffled cluck of guns cocked in preparation--then the sudden rush of motion, the din of another attack. This classic story seeks to illuminate a little-known theater of the Civil War--the cavalry battles of the Trans-Mississippi West, a region that included Missouri, Arkansas, Texas,...