A deeply divided border state, heir to the “Bleeding Kansas” era, Missouri became the third most fought-over state in the war, following Virginia and Tennessee. Rich in resources and manpower, critical politically to both the Union and the Confederacy, it was the scene of conventional battles, river warfare, and cavalry raids. It saw the first combat by organized units of Native Americans and African Americans. It was also marked by guerrilla warfare of unparalleled viciousness. This volume, the ninth in the series, includes hundreds of photographs, many of them never before published. The authors provide text and commentary, organizing the photographs into chapters covering the origins of the war, its conventional and guerrilla phases, the war on the rivers, medicine (Sweeny’s medical knowledge adds a great deal to this chapter and expands our knowledge of its practice in the west), the experiences of Missourians who served out of state, and the process of reunion in the postwar years.