The Presidential Succession Act of 1947 established the following order for succession to the presidency in the event that the President dies or resigns or becomes incapacitated while in office:
The Vice PresidentThe Speaker of the House of RepresentativesThe President pro tempore of the SenateThe heads of federal executive departments (the President's Cabinet) - in a specified order starting with the Secretary of State
There had been earlier Presidential succession acts. A 1792 act had placed the President pro tempore of the Senate next after the Vice President, and Speaker of the House after that. (The President pro tempore of the Senate is a Senator who is designated to lead the Senate in the absence of the Vice President, who serves as the usual President of the Senate.)
In 1881, Chester A. Arthur went from Vice President to President when James Garfield died. It happened during a time between sessions of Congress, and there was no Senate President pro tempore and no Speaker of the House. So it was seen as possible that there could be a time when there was no Vice President or President pro tem of the Senate or Speaker of the House. In 1886, Congress passed a Presidential Succession Act that went straight from the Vice President to Cabinet officials in order that their Cabinet office was created (in historical order).
The 1947 Presidential Succession Act was urged by President Harry Truman, after his succession to the Presidency after the death of Franklin D. Roosevelt. The 1947 Act put the Speaker of the House and the President pro tem of the Senate back in the order, but placed the Speaker of the House next in line after the Vice President.
