Birch Bayh, the liberal former senator from Indiana whose work in Congress had an enduring impact on American life — in protecting women from sex discrimination in education, guaranteeing 18-year-olds the right to vote and providing for the removal of a sitting president — died on Thursday at his home in Easton, Md.. He was 91.
The family announced his death in a statement. The cause was pneumonia, said a son, Christopher Bayh.
Mr. Bayh, a Democrat who served in the Senate from 1963 to 1981, was the principal architect of two constitutional amendments: the 25th, which dealt with presidential disability and vice-presidential vacancies, and the 26th, which gave 18-year-olds the vote in both state and federal elections.