Birch Evans Bayh Jr., an American politician, served as a member of the United States Senate from 1963 to 1981, affiliated with the Democratic Party.
Bayh's political career began in 1954 when he was first elected to the Indiana House of Representatives, and he was subsequently elected as Speaker in 1958, becoming the youngest person to hold that office in the state's history.
In 1962, Bayh ran for the U.S. Senate, narrowly defeating incumbent Republican Homer E. Capehart, and shortly after entering the Senate, he became Chairman of the United States Senate Judiciary Subcommittee on the Constitution.
As Chairman, Bayh authored two constitutional amendments: the Twenty-fifth, which establishes procedures for an orderly transition of power in the case of the death, disability, or resignation of the President of the United States, and the Twenty-sixth, which lowered the voting age to 18 throughout the United States.
With these accomplishments, Bayh became the first person since James Madison and only non–Founding Father to have authored more than one constitutional amendment.
Throughout his career, Bayh also led unsuccessful efforts to ratify the Equal Rights Amendment and eliminate the United States Electoral College.
