The landmark legislation that established social security in the United States was the Social Security Act of 1935. Signed into law by President Franklin D. Roosevelt during the Great Depression, the act aimed to provide economic security for older Americans and those unable to work due to disability. It introduced a system of federal welfare benefits, including old-age pensions, unemployment insurance, and aid to dependent children and the disabled. This fundamental social safety net has evolved over the years, becoming a crucial part of American social policy and significantly reducing poverty among the elderly, thereby transforming the nation's approach to social support and economic security.