The U.S. Senate, almost alone among legislative assemblies of the world, has had a unique tradition of unlimited debate called the filibuster. A filibuster is the use of time-consuming parliamentary tactics by one Senator or a minority of Senators to delay, modify, or defeat proposed legislation. It was not until 1917 that the Senate attempted to rein in unlimited debate when it adopted a cloture rule (Rule 22). The rule provided for two-thirds of the Senators to end debate on a particular subject. The first cloture vote was on the Treaty of Versailles debate. Senator Gilbert Hitchcock presented a cloture petition to the Senate on November 13, 1919 and two days later, cloture was adopted by a vote of 78-16, leading to a rejection of the treaty. In 1925, newly inaugurated Vice President Charles Dawes, the president of the Senate, unsuccessfully sought to change the number required for cloture to a simple majority of Senators. Dawes argued that “filibustering contributes to multiplicity of laws” and as a result of filibustering, “the laws which are passed often do not receive due consideration.” Political scientist Lindsay Rogers disagreed with Dawes; in fact, Rogers advocated the use of the filibuster in his 1926 book, The American Senate. The publication of The American Senate was received as an eloquent discourse on the tradition of unlimited debate and the rights of the minority. While legislation is often moved through the Senate through unanimous consent agreements, the importance of unlimited debate cannot be overstated. Rogers argued that “complete freedom of debate and the absence of closure except as a real emergency measure are more indispensable than in respect of legislation.” To Rogers, the power the minority could draw from unlimited debate was the only effective way the legislature could act as a check upon the executive branch. “. . . [U]nrestricted debate in the Senate is the only check upon presidential and party autocracy. The devices that the framers of the Constitution so meticulously set up would be ineffective without the safeguard of senatorial minority action.” Three quarters of a century later, as the world has changed and the Senate has evolved, the work remains an important window into the historic U.S. Senate.