Which piece of roosevelt’s legislation, passed in 1941, stirred up the most controversy?

I believe that the best answer for this question would be the Lend-Lease Act of 1941. This Act allowed Congress to authorize the sale, transfer, exchange, or lease of weapons and supplies to any country that the President deemed vitally important to the United States' defense. This Act would assist the British and other Allied forces in winning future battles, but it was controversial. Hope this helps.