As we have seen, the provision that there should be two senators from each State was the result of a compromise.  Consequently, New York and Pennsylvania have the same number as Delaware and Nevada.[17] The term of six years for senators was likewise a compromise measure.  There were members of the convention who favored three years; others wanted nine years, and Hamilton desired that the term should be during good behavior.  Many States have practically lengthened the prescribed term by the wise policy of returning acceptable senators for more than one term.

[Footnote 17:  The Senate now contains 96 members; the English House of Lords, 560; and the French Senate, 300.]

Prior to April 8, 1913, when the Seventeenth Amendment became a part of the Constitution, through ratification by the requisite votes of three-fourths of the State legislatures, senators were chosen by the State legislatures.  For years the demand for such an amendment was insistent.  More than two-thirds of the State legislatures had gone on record in favor of such a reform.  The House of Representatives had passed such a resolution a number of times, but the requisite two-thirds vote could not be secured in the Senate.  The leading reasons for the amendment were:  the frequent deadlocks in the legislatures, thus interrupting the course of regular legislation, and the use of bribery.

Classes of Senators and Vacancies.—­Section 3, Clause 2. Immediately after they shall be assembled in consequence of the first election, they shall be divided, as equally as may be, into three classes.  The seats of the senators of the first class shall be vacated at the expiration of the second year; of the second class, at the expiration of the fourth year; and of the third class, at the expiration of the sixth year; so that one-third may be chosen every second year.  When vacancies happen in the representation of any State in the Senate, the executive authority of such State shall issue writs of election to fill such vacancies.  Provided, that the legislature of any State may empower the executive thereof to make temporary appointments until the people fill the vacancies by election as the legislature may direct.

This amendment shall not be so construed as to affect the election or term of any senator chosen before it becomes valid as part of the Constitution.

This provision makes the Senate a permanent body, since only one-third of the members go out of office every two years.  In the first session of the first Congress, the senators were divided into three classes.  It has been the custom to place the senators from new States in different classes.  This is done in order to preserve, so far as possible, the equality of numbers in each class.  Besides, a State is thus enabled to keep one man of experience in the Senate.  When a new State is admitted, the senators from that State determine by lot, drawn in the presence of the Senate, which classes they are to enter.