Ever heard of David Rice Atchinson? In 1849, he served as the 12th president of the United States -- for one day.
[Although president James Polk left office as scheduled, because it was a Sunday, Zachary Taylor (the new president) was unable to take the oath until the following day. Rice, as president pro tempore of the Senate, served (as stipulated by the provisions of the Constitution) until Taylor was sworn in. He neither started a war nor levied any new taxes. He merely left without complaint after 24 hours.]
Sources
The Economist
