cloture

In 1917, Senators adopted a rule (Rule 22), at the urging of President Woodrow Wilson, that allowed the Senate to end a debate or filibuster with a two-thirds majority vote, a device known as "cloture." The new Senate rule was first put to the test in 1919. In 1975, the Senate reduced the number of votes required for cloture from two-thirds to three-fifths, or 60 of the current one hundred Senators.