Efforts to retain and regain peace during the Civil War (1861–1865) were uniformly unsuccessful. The earliest of these efforts took place in Washington in the winter of 1860–1861 as the outbreak of war threatened. Kentucky Senator John J. Crittenden drafted a series of initiatives, including an irrevocable constitutional amendment protecting slavery, protection of slavery south of the Missouri Compromise line, and compensation to owners for fugitive slaves. The Republican Party immediately rejected these proposals. Shortly thereafter, a peace convention of Unionists from the upper South met to try to find an alternative plan to prevent war. The convention adopted a modified form of the Crittenden plan that both the Republicans and the newly formed Confederate States of America rejected.

The initial organization of purely voluntary armies by both governments and the overwhelming martial spirit in both sections temporarily silenced peace advocates after April 1861. Individual pacifists, especially the Quakers...