Theodore  Roosevelt Jr. ( ROH-zə-velt; October 27, 1858 – January 6, 1919), often referred to as Teddy Roosevelt or his initials T.R., was an American statesman, politician, conservationist, naturalist, and writer who served as the 26th president of the United States from 1901 to 1909. . He served as the 25th vice president from March to September 1901 and as the 33rd governor of New York from 1899 to 1900. Roosevelt emerged as a leader of the Republican Party and became a driving force for the anti-trust policy while supporting Progressive Era policies in the United States in the early 20th century. . While at Harvard, Roosevelt began a systematic study of the role played by the young United States Navy in the War of 1812. Assisted by two uncles, he scrutinized original source materials and official U.S. Navy records, ultimately publishing The Naval War of 1812 in 1882.