The Presidential Line of Succession is specified in the Constitution and the Presidential Succession Act of 1947. The order of succession is: President, Vice-President, Speaker of the House, President pro Tempore of the Senate, Secretary of State and then through the cabinet in order of the original date of the formation of that office. Thus State, Treasury, Defense, Attorney General, Interior, Agriculture, Commerce, Labor, Health and Human Service, Housing and Urban Development, Transportation, Energy, Education, Veterans Affair, until you reach the end at the Secretary of Homeland Security. At that point, it goes back to Congress according to seniority.