The Great Depression in the United States was the worst and longest economic collapse in the history of the modern industrial world. It lasted from late 1929 until the early 1940s. Starting in the United States, the depression spread to most of the world's industrial countries, which had become economically dependent on each other by the 20th century. The Great Depression caused rapid declines in the production and sales of goods and a sudden and severe increase in unemployment. In 1933, at the worst of the Depression, more than 15 million Americans were unemployed. By entering the presidency in the midst of the Great Depression, Franklin D. Roosevelt helped the American people regain their self-confidence. He brought hope by promising swift and vigorous action and stating in his inaugural address, “the only thing we have to fear is fear itself.” Franklin D. Roosevelt was born in Hyde Park, New York, on January 30, 1882, the son of James Roosevelt and Sara Delano Roosevelt. He attended Groton, an impressive preparatory school in Massachusetts, and earned a history degree from Harvard in just three years. In 1905 he married a distant cousin, Anna Eleanor Roosevelt, who was the granddaughter of President Theodore Roosevelt. Roosevelt later moved to New York City and studied law at Columbia University in New York. He passed the bar exam in 1907 and left school without finishing his law degree. For the next three years he practiced law at a major law firm in New York City. He entered politics in 1910 and was elected as a Democrat to the New York State Senate. Roosevelt was re-elected to the State Senate in 1912 and supported Woodrow Wilson's candidacy at the Democratic National Convention. Wilson appointed him deputy secretary of the Navy in 1913 as a reward for his support, a position he held until 1920. Roosevelt's popularity and success in naval affairs led to his being nominated for vice president by the Democratic Party. However, Republican Warren Harding ascended to the presidency, and Roosevelt returned to private life. In the summer of 1921 Roosevelt contracted polio, which is infantile paralysis. Despite efforts to overcome his crippling illness, he never regained the use of his legs. With the encouragement and help of his wife, Eleanor, and his close political friend, Louis Howe, Roosevelt resumed his political career..