On March 8, 1917, the United States Senate passed Rule 22, the cloture rule, in an effort to limit filibustering in the Senate. Filibustering occurs when a senator or group of senators delay or entirely prevent a vote in the Senate by extending the debate on that proposal through continuously talking. Filibustering came into use in the Senate because Senate rules permit a senator, or a series of senators, to speak for as long as they wish and on any topic they choose. For example, a Senator can simply stand and read the phone book if they wish to delay a bill. There is no filibustering in the House of Representatives, which has a time limit on the debate of bills.

Despite this rule existing since 1806, there were no actual filibusters in the Senate until the late 1830s. In 1917, eleven Senators tried to filibuster a bill to arm U.S. merchant ships. President Woodrow Wilson urged the Senate to change its rules. Wilson wanted to prevent the delay of vote, not only for this bill, but for important bills in the future. In response, the Senate passed Rule 22 on March 8, 1917.

Rule 22, or the cloture rule, is a process aimed at bringing a debate to a quick end. When someone is filibustering in the Senate, the Senators can vote to invoke cloture, which will bring the filibuster to an end in a more timely fashion. Even if the cloture passes, 30 hours of debate are still allowed.

Originally, a two-thirds supermajority of all Senators present and voting was required on a cloture vote for it to pass. This proved to be quite difficult to achieve, so the rule was later changed to a three-fifths majority of all Senators currently in office.

The cloture rule was first invoked in 1919 to end the filibuster on the Treaty of Versailles which ended World War I.