The American Peace Mobilization was formed in 1940 to discourage any participation in World War II by the United States.
Many of its founders were acting in support of the Soviet Union, which was at that time aligned with Nazi Germany by the Hitler-Stalin pact. As such, the organization turned into an advocate for war immediately after the Soviet Union was invaded by the Nazis on June 22, 1941 — abruptly ending its 1,029-hour continuous peace demonstration in front of the White House.
It changed its name to American People's Mobilization until it closed down months later.
Frederick Vanderbilt Field was its executive secretary. Congressman Vito Marcantonio was one of its vice chairs.