Franklin D. Roosevelt, often referred to by his initials FDR, was an American politician who served as the 32nd president of the United States from 1933 until his death in 1945.

Roosevelt won a record four presidential elections and became a central figure in world events during the first half of the 20th century. After his death, the Twenty-Second Amendment was passed by Congress and ratified by the states, limiting presidents to two terms for a total of eight years.

Franklin's mother Sara was born Sara Ann Delano. She was the dominant influence in Franklin's early years and once declared, "My son Franklin is a Delano, not a Roosevelt at all."

Despite his admiration for his cousin Theodore, Franklin inherited his father's affinity for the Democratic Party.

In 1905, he married his fifth cousin once removed, Eleanor Roosevelt. They had six children, of whom five survived into adulthood.

Roosevelt had various extra-marital affairs, including one with Eleanor's social secretary Lucy Mercer, which began soon after she was hired in early 1914. In September 1918, Eleanor found letters revealing the affair in Roosevelt's luggage. Roosevelt promised never to see Lucy again, but Eleanor never truly forgave him, and their marriage from that point on was more of a political partnership. Eleanor established a separate home in Hyde Park and increasingly devoted herself to various social and political causes independently of her husband. The emotional break in their marriage was so severe that when Roosevelt asked Eleanor in 1942--in light of his failing health--to come back home and live with him again, she refused.

Roosevelt was James M. Cox's running mate on the Democratic Party's 1920 national ticket, but Cox was defeated by Republican Warren G. Harding.

While the Roosevelts were vacationing at Campobello Island in August 1921, he fell ill and was diagnosed with polio. Although he was left permanently paralyzed from the waist down, Roosevelt convinced many people that he was improving, which he believed to be essential prior to running for public office again. He laboriously taught himself to walk short distances by swiveling his torso while wearing iron braces and supporting himself with a cane.

He served as governor of New York from 1929 to 1933, promoting programs to combat the economic crisis besetting the United States after the Wall Street Crash of 1929.

Against the backdrop of the Great Depression, Roosevelt defeated Republican President Herbert Hoover in a landslide, winning 57% of the popular vote and carrying all but six states.