Who was the president in 1909?

This depends on the country/organization. See related questions.

US: Theodore (Teddy) Roosevelt to March 4, then William Howard Taft.

Theodore Roosevelt was the 26th President of the United States from 1901 September 14 to 1909 March 4. He would later break with the Republican party after the renomination of Taft, forming the Progressive (Bull Moose) Party, and unsuccessfully running for president a third time.

William Howard Taft was the 27th President of the United States from 1909 March 4 to 1913 March 4. After his re-nomination in 1912 and the break of Roosevelt from the core of the Republicans, the Republican Party was destroyed in the election, ceding the presidency to Woodrow Wilson and the Democrats.