Theodore Roosevelt (October 27, 1858 – January 6, 1919) was the 26th president of the United States from 1901 to 1909. In September 1901, President William McKinley was assassinated, and Roosevelt became president at the age of 42, taking office at the youngest age of any U.S. president in history at that time. Roosevelt was a hero of the Spanish–American War and the Battle of San Juan Hill for which he received the Medal of Honor and was the commander of the legendary Rough Riders. He negotiated an end to the Russo-Japanese War which later won him the Nobel Peace Prize. Roosevelt was the first American to win the Nobel Peace Prize.