Basic Info: Passed on March 11, 1941, this act set up a system that would allow the United States to lend or lease war supplies to any nation deemed "vital to the defense of the United States."
Why: Proposed in late 1940 and passed in March 1941, the Lend-Lease Act was the principal means for providing U.S. military aid to foreign nations during World War II
It's debated; the credit is usually given to either Julia Ward Howe or Anna Jarvis. Howe was born first, so if you're looking for initial efforts, I would go with her.