The United States Senate is the upper chamber of the United States Congress, which along with the United States House of Representatives—the lower chamber—comprise the legislature of the United States.
The composition and powers of the Senate are established by Article One of the United States Constitution. The Senate is composed of senators, each of whom represents a single state in its entirety, with each state being equally represented by two senators, regardless of its population, serving staggered terms of six years; with 50 states currently in the Union, there are 100 U.S. Senators. From 1789 until 1913, Senators were appointed by legislatures of the states they represented; following the ratification of the Seventeenth Amendment in 1913, they are now popularly elected. The Senate chamber is located in the north wing of the Capitol, in Washington, D.C.