The Presidency of Theodore Roosevelt on September 14, 1901, when Theodore Roosevelt became the 26th President of the United States upon the assassination and death of President William McKinley, and ended on March 4, 1909. Roosevelt had been the Vice President of the United States for only 194 days when he succeeded to the presidency. A Republican, he ran for and won a full four-year term as president in 1904, easily defeating Democratic nominee Alton B. Parker. After the Republican victory in the 1908 presidential election, Roosevelt was succeeded by his protégé and chosen successor, William Howard Taft.