<P> Until 1971, the Postmaster General, the head of the Post Office Department, was a member of the Cabinet, initially the last in the presidential line of succession before new officers were added . Once the Post Office Department was re-organized into the United States Postal Service, a special agency independent of the executive branch, the Postmaster General ceased to be a member of the Cabinet and was thus removed from the line of succession . </P> <P> The United States Department of Homeland Security was created in 2002 . On March 9, 2006, pursuant to the renewal of the Patriot Act as Pub. L. 109--177, the Secretary of Homeland Security was added to the line of succession . The order of Cabinet members in the line has always been the same as the order in which their respective departments were established . Despite custom, many in Congress had wanted the Secretary to be placed at number eight on the list--below the Attorney General, above the Secretary of the Interior, and in the position held by the Secretary of the Navy prior to the creation of the Secretary of Defense--because the Secretary, already in charge of disaster relief and security, would presumably be more prepared to take over the presidency than some of the other Cabinet secretaries . Despite this, the 2006 law explicitly specifies that the "Secretary of Homeland Security" follows the "Secretary of Veterans Affairs" in the succession, effectively at the end of the list . </P> <P> While nine vice presidents have succeeded to the office upon the death or resignation of the president, and two vice presidents have temporarily served as acting president, no other officer has ever been called upon to act as president . On March 4, 1849, President Zachary Taylor's term began, but he declined to be sworn in on a Sunday, citing religious beliefs, and the vice president was not sworn either . As the last President pro tempore of the Senate, David Rice Atchison was thought by some to be next in line after the vice president, and his tombstone claims that he was US President for the day . However, Atchison took no oath of office to the presidency either, and his term as Senate President pro tempore had by then expired . </P> <P> In 1865, when Andrew Johnson assumed the presidency on the death of Abraham Lincoln, the office of vice president became vacant . At that time, the Senate President pro tempore was next in line to the presidency . In 1868, Johnson was impeached by the House of Representatives and subjected to trial in the Senate, and if he had been convicted and thereby removed from office, Senate President pro tempore Benjamin Wade would have become Acting President . This posed a conflict of interest, as Wade's "guilty" vote could have been decisive in removing Johnson from office and giving himself presidential powers and duties . Johnson was acquitted by a one - vote margin . </P>

Who becomes president if the current president is impeached