What is the name of he act that created the rules for succession of the president?

The act that established the rules for presidential succession is called the Presidential Succession Act. Initially passed in 1792 and revised several times, the most significant update came in 1967 with the 25th Amendment to the U.S. Constitution, which clarified the line of succession following the president and vice president. This framework outlines who assumes the presidency in the event of death, resignation, or removal from office.