Many socialist groups and movements believed in nonviolence in the 19th century. They were mainly against war because it seemed to be a way of manipulating the working class to benefit the bourgeoisie of the capitalist system. Several groups continued to protest war even when other socialist groups supported the wars of their country. Some other institutions that stood up to violence at the time included the traditional peace churches, the Woman's Peace Party, the International Committee of Women for Permanent Peace (ICWPP), American Union Against Militarism, the Fellowship of Reconciliation, and the American Friends Service Committee.
The first woman to be elected to Congress, Jeanette Rankin, stood up against war and held very firmly the ideas of pacifism, and was the only person who voted against entering in both World Wars. After World War I, peace groups began to erupt, including the War Resisters' International and the Women's International League for Peace and Freedom. At the beginning of World War II, pacifism became less popular in places that were wracked by war.
Conscientious objectors also played a huge role in both World Wars. Some objectors were allowed to work in nonviolent roles in the military, while others who were less willing to comply were forced into federal prisons during the war.