The Neutrality Acts of 1935 and 1937 restricted travel and the trade of between the United States and nations at war.

The Neutrality Acts, 1930s ... On August 31, 1935, Congress passed the first Neutrality Actprohibiting the export of "arms, ammunition, and implements ofwar" from the United States to foreign nations at war and requiring arms manufacturers in the United states to apply for an export license