The leader who implemented the New Deal during the Great Depression was Franklin D. Roosevelt. Taking office in 1933, he introduced a series of programs and policies aimed at recovering the economy and providing relief to millions suffering from the economic collapse. The New Deal included initiatives like Social Security, infrastructure projects, and regulations on banking and finance. Roosevelt’s bold approach shifted the role of government in economic and social welfare, laying the groundwork for the modern American state and establishing a legacy of federal involvement in economic issues.