<P> The lend - lease policy, formally titled "An Act to Promote the Defense of the United States", (Pub. L. 77--11, H.R. 1776, 55 Stat. 31, enacted March 11, 1941) was a program by which the United States supplied Free France, the United Kingdom, the Republic of China, and later the Soviet Union and other Allied nations with food, oil, and materiel between 1941 and August 1945 . This included warships and warplanes, along with other weaponry . The policy was signed into law on March 11, 1941 and ended during September 1945 . The aid was free for some countries, although some countries were repaying with gold, and some military equipment were required to be returned after the war . In return for the aid, the U.S. was given leases on army and naval bases in Allied territory during the war . </P> <P> A total of $50.1 billion (equivalent to $681 billion presently) worth of supplies was shipped, or 11% of the total war expenditures of the U.S. In all, $31.4 billion (equivalent to $427 billion today) went to Britain and its Empire, $11.3 billion (equivalent to $154 billion today) to the Soviet Union, $3.2 billion (equivalent to $43.5 billion today) to France, $1.6 billion (equivalent to $21.7 billion today) to China, and the remaining $2.6 billion to the other Allies . Reverse lend - lease policies comprised services such as rent on air bases that went to the U.S., and totaled $7.8 billion; of this, $6.8 billion came from the British and the Commonwealth . The terms of the agreement provided that the materiel was to be used until returned or destroyed . In practice very little equipment was returned . Supplies that arrived after the termination date were sold to Britain at a large discount for £ 1.075 billion, using long - term loans from the United States . Canada operated a similar program called Mutual Aid that sent a loan of $1 billion and $3.4 billion in supplies and services to Britain and other Allies . </P>

When did the united states congress pass the lend-lease act