James K. Polk, American lawyer and politician, 11th President of the United States (born 1795)

James Knox Polk was the 11th president of the United States, serving from 1845 to 1849. A protégé of Andrew Jackson and a member of the Democratic Party, he was an advocate of Jacksonian democracy and American expansionism. Polk saw Texas join the Union in his first year in office, one of the precipitating causes that soon led the U.S. into the Mexican–American War. The settlement of that war expanded American territory to the Pacific Ocean. During his term, the dispute over the Oregon Territory, with Great Britain was also resolved, creating the present U.S.-Canadian boundary.

The president of the United States (POTUS) is the head of state and head of government of the United States. The president directs the executive branch of the federal government and is the commander-in-chief of the United States Armed Forces.