So... at any given time, who was "Next In Line?"

Below is an unofficial list, applying either the Constitution or the appropriate supporting federal law in place at the time (e.g., the Presidential Succession Acts of 1792, 1886 or 1947), of those persons first in the presidential line of succession, the dates they held that role, the office that person held which placed them first in line, and the circumstances by which they were at the top of the list.

For the first 23 years of our national government the Vice President was "next in line," but that would change with the death of Vice President George Clinton on April 20, 1812.  And in the two centuries since, on over 80 occasions the person "next in line" has changed, with many people being "next in line" on multiple occasions, sometimes serving in different offices placing them there.