Theodore  Roosevelt Jr. ( ROH-zə-velt; October 27, 1858 – January 6, 1919), sometimes referred to by 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. Theodore  Roosevelt Jr. ( ROH-zə-velt; October 27, 1858 – January 6, 1919), sometimes referred to by 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. ... He gloried in war, was thrilled by military history, and placed warlike qualities high in his scale of values.