Video: 'History of the Filibuster'

(Thursday, March 8, 1917) — The U.S. Senate today passed Rule 22, the cloture rule, in an effort to limit filibustering in the Senate by a 76-3 vote.

The Senate’s cloture rule originally required a super-majority of two-thirds of all senators “present and voting” to be considered filibuster-proof.

In 1975, the Democratic Senate majority reduced the necessary supermajority to three-fifths.