“If we repeal it, we are helping England and France. If we fail to repeal it, we will be helping Hitler and his allies. Absolute neutrality is an impossibility.”

Senator George W. Norris on the repeal of the
Neutrality Acts, 1939

Between 1935 and 1937 Congress passed three "Neutrality Acts" that tried to keep the United States out of war, by making it illegal for Americans to sell or transport arms, or other war materials to belligerent nations. Supporters of neutrality, called "isolationists" by their critics, argued that America should avoid entangling itself in European wars. "Internationalists" rejected the idea that the United States could remain aloof from Europe and held that the nation should aid countries threatened with aggression.

In the spring of 1939, as Germany, Japan, and Italy pursued militaristic policies, President Roosevelt wanted more flexibility to meet the Fascist challenge. FDR suggested amending the act to allow warring nations to purchase munitions if they paid cash and transported the goods on non-American ships, a policy that favored Britain and France. Initially, this proposal failed, but after Germany invaded Poland in September, Congress passed the Neutrality Act of 1939 ending the munitions embargo on a "cash and carry" basis.

The passage of the 1939 Neutrality Act marked the beginning of a congressional shift away from isolationism. Over the next 2 years, Congress took further steps to oppose fascism. One of the most important was the 1941 approval of Lend-Lease, which allowed the United States to transfer arms to nations vital to the national defense.