Theodore "Teddy" Roosevelt (October 27, 1858 – January 6, 1919) was the 26th President of the United States (1901–1909). He is noted for his exuberant personality, range of interests and achievements, and his leadership of the Progressive Movement, as well as his "cowboy" persona and robust masculinity. He was a leader of the Republican Party and founder of the first incarnation of the short-lived Progressive ("Bull Moose") Party of 1912. Before becoming President, he held offices at the city, state, and federal levels. Roosevelt's achievements as a naturalist, explorer, hunter, author, and soldier are as much a part of his fame as any office he held as a politician. Roosevelt was 42 years old when sworn in as President of the United States in 1901, making him the youngest president ever; he beat out the youngest elected president, John F. Kennedy, by only one year. Roosevelt was also the first of only three sitting presidents to have won the Nobel Peace Prize.
Born into a wealthy family in New York City, Roosevelt was a sickly child who suffered from asthma and stayed at home studying natural history. To compensate for his physical weakness, he embraced a strenuous life. Home-schooled, he became an eager student of nature. He attended Harvard University, where he studied biology, boxed and developed an interest in naval affairs. In 1881, one year out of Harvard, he was elected to the New York State Assembly, where he became a leader of the reform faction of his Republican Party (the "GOP"). His The Naval War of 1812 (1882) established his professional reputation as a serious historian; he wrote numerous books on hunting, the outdoors, and current political issues, as well as frontier history. In 1884, his wife and his mother died on the same day. He left politics and went to the frontier, becoming a rancher in the "Badlands" in the Dakotas. Returning to New York City, he ran for mayor in 1886, finishing third with 60,000 votes. He later gained fame by taking vigorous charge of the city police. At the national level, he was a leader in civil service reform. The Spanish–American War broke out in 1898 while Roosevelt was, effectively, running the Department of the Navy. He promptly resigned and formed the Rough Riders – a volunteer cavalry regiment that fought in Cuba. The war hero was elected governor in 1898 and in 1900 was nominated for vice president. He successfully energized the GOP base as a highly visible campaigner to reelect President William McKinley on a platform of high tariffs, the gold standard, imperialism, prosperity at home and victory abroad.
In 1901, President William McKinley was assassinated and Roosevelt became President at the age of 42; he remains the youngest president. Roosevelt attempted to move the Republican Party (GOP) toward Progressivism, including trust busting and increased regulation of businesses. Roosevelt was elected in 1904 to a full term of his own, the first person to do so from the Vice-Presidency, winning the largest percentage of the popular vote since the uncontested election of 1820. Roosevelt coined the phrase "Square Deal" to describe his domestic agenda, emphasizing that the average citizen would get a fair share under his policies. As an outdoorsman and naturalist, he promoted the conservation movement. On the world stage, Roosevelt's policies were characterized by his slogan, "Speak softly and carry a big stick". Roosevelt was the force behind the completion of the Panama Canal; sent the Great White Fleet on a world tour to demonstrate American power; and negotiated an end to the Russo-Japanese War, for which he won the Nobel Peace Prize.
At the end of his second term, Roosevelt promoted his friend William Howard Taft for the 1908 Republican nomination. He toured Africa and Europe. On his return in 1910 he broke bitterly with President Taft on issues of progressivism and personalities. In the 1912 election Roosevelt tried and failed to block Taft's renomination. He launched the Bull Moose Party that called for far-reaching progressive reforms. He lost to Democrat Woodrow Wilson, as the Taft conservatives gained control of the Republican party for decades to come. Roosevelt led a major expedition to the Amazon jungles but contracted diseases which ruined his health. He died relatively young at the age of sixty. Roosevelt has consistently been ranked by scholars as one of the greatest U.S. Presidents, having revived a declining presidency.