Who were the resistance movements in World War 2?

There was a communist organization called "The American Peace Mobilization". It was considered a "subersive" group by the government. They were very anti-war until Germany invaded the Soviet Union. After that, they supported the Soviet's entry into the war and they supported material aid to the Soviets by the United States. Isolationism was also a very strong anti-war philosophy spearheaded by Charles Limburg. Once the Japanese attacked Pearl Harbor, they groups quickly quieted down. that's about all I know about anti-war groups during World War 2.