Capitalist development involves ongoing technological changes in which a series of innovations develop and diffuse. Wars and other discontinuities periodically break the process, thwarting some innovations and generating others. Wartime experience hence illuminates the question of whether innovation responds to the changing economic environment or maintains earlier directions. The paper examines the roles of peacetime factors and wartime dislocations in the development of three Civil War innovations, firearms, shoe mechanization, and petroleum. Using patent data, government procurement records, and selected firm records to compare antebellum and wartime activities, I argue for the continuity of innovation in its content and in the occupation, network status, and location of patentees. Wartime innovation evolved out of antebellum firms, networks, and inventors. It drew on machinists, engineers, and applied scientists to transfer critical antebellum capabilities into innovating sectors. The war accelerated innovations in firearms and shoe mechanization and may have slowed petroleum innovation. Whereas the North continued antebellum innovation processes during the war, the South, with little capability in any of the sectors, was unable to innovate successfully even when military need was strong.