Richard Mentor Johnson ( October 17 , 1780 â `` November 19 , 1850 ) was the ninth Vice President of the United States , serving with President Martin Van Buren . Richard Mentor Johnson ( October 17 , 1780 or 1781 -- November 19 , 1850 ) was the ninth Vice President of the United States , serving in the administration of Martin Van Buren ( 1837 â `` 1841 ) .