Franklin Delano Roosevelt (/ˈroʊzəvəlt/, his own pronunciation,[1] or /ˈroʊzəvɛlt/) (January 30, 1882 – April 12, 1945), commonly known by his initials FDR, was an American statesman and political leader who served as the 32nd President of the United States.[2] A Democrat, he won a record four elections and served from March 1933 to his death in April 1945. He was a central figure in world events during the mid-20th century, leading the United States during a time of worldwide economic depression and total war. His program for relief, recovery and reform, known as the New Deal, involved the great expansion of the role of the federal government in the economy. A dominant leader of the Democratic Party, he built the New Deal Coalition that united labor unions, big city machines, white ethnics, African Americans, and rural white Southerners. The Coalition realigned American politics after 1932, creating the Fifth Party System and defining American liberalism for the middle third of the 20th century.

Roosevelt was born in 1882 to an old, prominent Dutch family from upstate New York. He attended the elite schools of Groton School and Harvard College. In 1905, he married Eleanor Roosevelt, with whom he had six children. He entered politics in 1910, serving in the New York State Senate, and then as Assistant Secretary of the Navy under President Woodrow Wilson. In 1920, Roosevelt ran for vice president alongside presidential candidate James M. Cox but the Cox/Roosevelt ticket lost to the Republican ticket of Warren Harding and Calvin Coolidge. Roosevelt was stricken with polio in 1921, which cost him the use of his legs and put his political career on hold for several years. Roosevelt attempted to recover from this illness, and founded a treatment center for polio patients in Warm Springs, Georgia. After returning to political life by placing Alfred E. Smith's name into nomination at the 1924 Democratic National Convention, Roosevelt was asked by Smith to run for Governor of New York in the 1928 election. Roosevelt served as a reform governor from 1929 to 1932, and promoted the enactment of programs to combat the Great Depression that occurred during his governorship.

Roosevelt defeated incumbent Republican president Herbert Hoover in November 1932, at the depth of the Great Depression. Energized by his personal victory over polio, FDR used his persistent optimism and activism to renew the national spirit.[3] In his first hundred days in office, which began March 4, 1933, Roosevelt spearheaded major legislation and issued a profusion of executive orders that instituted the New Deal—a variety of programs designed to produce relief (government jobs for the unemployed), recovery (economic growth), and reform (through regulation of Wall Street, banks and transportation). He created numerous programs to support the unemployed and farmers, and to encourage labor union growth while more closely regulating business and high finance. The repeal of Prohibition added to his popularity, helping him win reelection by a landslide in 1936. The economy improved rapidly from 1933 to 1937, but then relapsed into a deep recession in 1937–38. The bipartisan Conservative Coalition that formed in 1937 prevented his packing the Supreme Court, blocked all proposals for major liberal legislation (apart from a minimum wage law), and abolished many of the relief programs when unemployment practically vanished during World War II. Most of the regulations on business continued in effect until they ended about 1975–1985, except for the regulation of Wall Street by the still existing Securities and Exchange Commission. Along with several smaller programs, major surviving programs include the Federal Deposit Insurance Corporation and Social Security.

As World War II loomed after 1938, with the Japanese invasion of China and the aggression of Nazi Germany, Roosevelt gave strong diplomatic and financial support to China and the United Kingdom, while remaining officially neutral. His goal was to make America the "Arsenal of Democracy", which would supply munitions to the Allies. In March 1941, Roosevelt, with Congressional approval, provided Lend-Lease aid to Britain and China