Theodore Roosevelt attended Harvard University, where he graduated in 1880. That same year he married Alice H. Lee, a woman from Massachusetts. She died in the year 1884, only hours after Theodore's mother had died. However, in less than three years he married Edith Kermit Carow. Roosevelt was very interested in politics and writing. He served three one-year terms in the New York Assembly in the years 1882-84. There he became known as an independent Republican. He supported civil service reform, legislation to benefit working people, and the bills designed to improve the government of New York City. After living two years as a rancher in the Dakota Territory, he returned in 1886 and ran for mayor in New York City. Teddy had many ways to have fun but one of them was camping, he loved going camping. It was like one of his hobbies.

Roosevelt's career blossomed in the next 10 years. After 2 years he was back in Washington as an assistant secretary of the navy. He helped organize the Rough Riders during the Spanish-American War in the year 1898 in Cuba. Later on that year he was nominated for governor of New York by Thomas Collier Platt, boss of New York's Republican Party. He ended up winning the election that fall.

Roosevelt's governorship (1899-1900) prepared him well for high office in Washington. He steered a middle course between subservience to the political machine and independent reformism, also he championed civil service , backed a measure to tax corporation franchises,and approved several bills supportive of labor and social reform. Between 1880 and 1900, he wrote dozens of books, magazines, histories, articles and, biographies. After serving three years in the assembly he left politics briefly because of the death of his wife and because he had alienated the reform wings of his party, on that year he needed to support James G. Blames for presidency. Between1882 and 1884, he was a New York State Assemblyman. Roosevelt also was a member of the U.S. Civil Service Commission from 1889-1895.

From 1895-1897 he was president of New York Police Board. He rooted out corruption in the police department, he described that as "utterly demoralized". Roosevelt also worked as an assistance secretary of the navy from 1897-1898 appointed by president William McKinley. He received an annual salary of $4,500. In 1898 he started as Governor of New York until 1900 with the support of the Republican Party. Theodore was Vice-President from March to September of the year 1901. He was a very important man in the U.S. community.

The Spanish-American war made Roosevelt a nationally known figure when he was a member of the Rough Riders.

He resigned his post to become Commander of the U.S. Volunteer Cavalry Regiment.