10. John Tyler was the first un-elected president to ascend to the office
The death of William Henry Harrison was expected by April 1, 1841, and Vice-President John Tyler was at his home in Williamsburg, Virginia when he learned of the possibility of opposition to his accession among party leaders. Tyler had been a compromise choice for Vice President to attract southern votes. Upon Harrison’s death Tyler had the oath of office administered as quickly as possible and moved into the White House. Throughout his presidency he was referred to by his opponents as “His Accidency”. Tyler’s presidency was marked by the first attempt by the House to open impeachment proceedings, and the first override of a presidential veto.