David Rice Atchison was a mid-19th Century US Senator from Missouri. His biggest claim to fame is that he may have been a US president for a day, that day being March 4, 1849. He was born in Frogtown, Kentucky, and educated at Transylvania University is Lexington, Kentucky. He became a lawyer, a strong pro-slavery advocate and the leader of the Border Ruffians, a mob dedicated to preserving slavery.
Atchison himself never claimed that he was technically president. Outgoing President Polk's term ended at noon on March 4, which was a Sunday. His successor, Zachary Taylor, refused to be sworn into office on a Sunday. As President Pro Tem of the Senate and therefore the Acting Vice-President, under the presidential succession law in place at the time, Atchison was believed by some to be the Acting President.
In his own words:
"It was in this way: Polk went out of office on the 3rd of March 1849, on Saturday at 12 noon. The next day, the 4th, occurring on Sunday, Gen. Taylor was not inaugurated. He was not inaugurated till Monday, the 5th, at 12 noon. It was then canvassed among Senators whether there was an interregnum (a time during which a country lacks a government). It was plain that there was either an interregnum or I was the President of the United States being chairman of the Senate, having succeeded Judge Mangum of North Carolina. The judge waked me up at 3 o'clock in the morning and said jocularly that as I was President of the United States he wanted me to appoint him as secretary of state. I made no pretense to the office, but if I was entitled in it I had one boast to make, that not a woman or a child shed a tear on account of my removing any one from office during my incumbency of the place. A great many such questions are liable to arise under our form of government." (Data taken from article on wikipedia.org. Thanks to a friend for making me aware of this anomaly.)
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