He was born in Frogtown, Kentucky on August 11, 1807, attended a University in Lexington and studied law. He was a Senator for Missouri; member of the state house of representatives in 1834 and in 1838; the judge of the Platte County circuit court in 1841, and chairman of the Committee on the Militia. He died at his home January 26, 1886 in Plattsburg, MO.
Atchison served as unofficial President of the United States for a day on Sunday – March 4, 1849. Vice-President George Dallas had resigned, leaving Atchison (President of the Senate) next in line for the Presidency. James Polk resigned his office a day early to head home to Tennessee and Zachary Taylor refused to take the Oath of Office on a Sunday for religious reasons. Although Atchison never took the Oath of Office, his tombstone does list him as President for that day. What is more interesting is that history records that, because of fatigue from inaugural partying the night before, Atchison slept through the entire day of his Presidency.