Theodore Roosevelt joined the Republican Party. One year later he was elected to be in the New York Assembly and he served three one year terms. He was then reelected in the New York Assembly to be the Minority Leader. In June 1884 he attended the Republican National Convention as a delegate.

On November 2, 1886, Teddy was defeated by Peter Cooper. They were both running for mayor of New York City. From May 7, 1889 until May 5, 1895, he was a U.S. Civil Service Commissioner in Washington. On May 5, 1895, he resigned from U.S. Service Civil Commissioner to become a Police Commissioner. The next day he was the President of the Board of Police Commissioners, New York City. On April 19, 1897, he was appointed Assistant Secretary of the Navy by President McKinley. A year later he resigned from Assistant Secretary of the Navy. At the same time he became the Lieutenant-Colonel of the 1st US Volunteer Calvary Regiment also know as the Rough Riders. He was elected by the Republican party for Governor of New York on September 27, 1898 and ran his opening campaign on October 5. He won by 17,794 votes. On December 31, 1898 he took oath to office. He was governor for two years. Teddy was elected Vice President and he won. He was Vice President from May 4 until September 14. He was only the Vice President for a short time because President William McKinley was shot in Buffalo, NY. So at the age of 42, Theodore became president of the United States of America until March 4, 1909. He was the 26th president. He made the speech "Citizenship in a Republic" on April 23, 1910. He served as a special ambassador for England at the funeral of King Edward VII.