Willie Person Mangum

Willie Person Mangum (; May 10, 1792 – September 7, 1861) was an American politician and planter who served as U.S. Senator from the state of North Carolina between 1831 and 1836 and between 1840 and 1853. He was one of the founders and leading members of the Whig party, and was a candidate for president in 1836 as part of the unsuccessful Whig strategy to defeat Martin Van Buren by running four candidates with local appeal in different regions of the country.
Most notably, Mangum served as President pro tempore of the Senate for most of John Tyler’s presidency, between 1842 and 1845. He was, therefore, first in the presidential line of succession during this time, as Tyler did not have a vice president. (There was no constitutional mechanism for filling an intra-term vice presidential vacancy at the time.) Had Tyler died, resigned or been removed from office at any time during his presidency, Mangum would have become acting president of the United States.