Franklin D. Roosevelt was the leader known for implementing the New Deal in the United States during the Great Depression. Elected as President in 1932, he introduced a series of programs and policies designed to provide relief for the unemployed, stimulate economic recovery, and reform the financial system. The New Deal encompassed a variety of initiatives, including the establishment of Social Security, public works projects, and banking reforms. Roosevelt's bold approach helped reshape the role of the federal government and provided a safety net for Americans in need. His leadership during this challenging period had a lasting impact on American politics and society, contributing to the modernization of the U.S. economy.