Because he was the only president that actually worked.
Polk
John Tyler preceded Polk as US president.
Polk succeeded John Tyler as President.
James K. Polk was 49 when he became president.
James K. Polk (term 1845-1849) was President of the United States during the Mexican-American War.
President Polk was responsible for the Mexican American War.
Zachary Taylor was next after Polk.
James Knox Polk.
Polk was active in Tennessee politics when he ran for President.
U.S President James K. Polk.
Polk was president before Lincoln
James Knox Polk was a U.S President from the Democratic Party. He was the Eleventh president of our country.