Theodore Roosevelt Jr., often referred to as Teddy or his initials T. R., was an American statesman, conservationist, naturalist, historian, and writer, who served as the 26th president of the United States from 1901 to 1909. He previously served as 33rd governor of New York from 1899 to 1900 and the 25th vice president of the United States from March to September 1901. Roosevelt emerged as a leader of the Republican Party and became a driving force for anti-trust and Progressive policies.
Roosevelt was a sickly child with debilitating asthma but partly overcame his health problems by embracing a strenuous lifestyle. He integrated his exuberant personality, a vast range of interests and achievements into a "cowboy" persona defined by robust masculinity. He was home-schooled and began a lifelong naturalist avocation before attending Harvard. His book The Naval War of 1812 established his reputation as a learned historian and popular writer. Upon entering politics, he became the leader of the reform faction of Republicans in New York's state legislature. His wife and mother both died in rapid succession, and he began to frequent a cattle ranch in the Dakotas.