Which U.S. President, despite facing significant economic challenges and skepticism, spearheaded the creation of a groundbreaking program that put young Americans to work conserving natural resources and building infrastructure during a period of immense hardship?

1. He served an unprecedented four terms in office.
2. His policies are often associated with the 'New Deal'.
3. He led the nation through World War II.
4. He suffered from polio and established a foundation dedicated to fighting the disease.