On Tuesday, Sept. 25, Speaker Nancy Pelosi announced the House would begin a formal impeachment inquiry into President Donald Trump's dealings with Ukraine President Volodymyr Zelensky. But who takes office if he, and potentially other members of his cabinet, are removed from office? The Presidential Succession Act sets up a line of succession that runs all the way from the vice president to the secretary of homeland security. The order has not always been agreed upon, and the law has a long history of changes, with the last one taking place in 2006.

The first iteration of the Presidential Succession Act in 1792 stated the Senate president pro tempore would be next in line after the vice president. On July 18, 1947, President Harry Truman signed the Presidential Succession Act of 1947. This act changed the line of succession in two ways: First, it reinstated the Senate president pro tempore and speaker of the House to the succession plan. Secondly, it also placed the speaker of the House right after the vice president instead of the Senate president pro tempore. The last change to the act came in 2006, when the USA Patriot Improvement and Reauthorization Act of 2005 added the secretary of homeland security to the list.

In Trump's administration, here's the full line of succession: