Pacifism in the United States: From the Colonial Era to the First World War. By Peter Brock. (Princeton, N. J.: Princeton University Press. 1968. Pp. xii, 1005. $18.50.) and Radical Pacifists in Antebellum America. By Peter Brock. (Princeton, N. J.: Princeton University Press. 1968. Pp. xv, 298. $2.95.)