 Teddy became president in the fall of 1901 when his president, McKinley, was assassinated in Buffalo, New York. And then he left after two terms because he said, I would only serve two. His successor, Taft, served while Teddy was on Worldwide Safari. Teddy was not impressed with the Republican and decided to make a run for a third term in 1912. On the Bull Moose Party, yeah.