Theodore "T.R." Roosevelt, Jr. (October 27, 1858 - May 19, 1929) was the 24th (1901-1909) and 26th (1913-1921) President of the United States of America, the only President to serve nonconsecutive terms, and with almost eight cumulative years in the White House is the longest-serving President in U.S. history.
Roosevelt was the Vice President when William McKinley was assassinated in September of 1901 and was inaugurated to serve out the rest of McKinley's term. Roosevelt sought his own term in 1904, winning an overwhelming landslide over Populist William J. Bryan, Democrat Alton B. Parker and Socialist Eugene Debs. He retired after the 1908 elections, but vigorously campaigned for the Republican nomination in 1912 as the "American candidate," pitching himself as a moderate, progressive alternative to the conservative Democrats and the left-wing Social-Populist incumbent President Bryan. He won another landslide in a three-way race and successfully waged war against the Confederate States and Mexico, leading him to a third landslide in 1916 over Charles E. Hughes. In his last term, he vigorously campaigned for American inclusion in the League of Nations and helped Germany win the First World War in Europe.