The U.S. supplied materiel to its allies during WWII through this 1941 Congressional act
Under the terms of "lend-lease," these 
allies would repay the United States not in money but by ... President Franklin 
Roosevelt wanted to aid the Western democracies in their fight against the Nazi 
and ... Congress did require lend-lease be carried out through annual 
appropriations... [DOC] [TLE] World War II and the American Home Front - National Park Service [PAR] courtesy of the Library of Congress, Prints & Photographs Division.