Article One of the Constitution of the United States establishes the legislative branch of the federal government, the United States Congress. Under Article One, Congress is a bicameral legislature consisting of the House of Representatives and the Senate. Article One grants Congress enumerated powers and the ability to pass laws "necessary and proper" to carry out those powers. Article One also establishes the procedures for passing a bill and places limits on the powers of Congress and the states from abusing their powers.
Article One's Vesting Clause grants all federal legislative power to Congress and establishes that Congress consists of the House of Representatives and the Senate. In combination with the vesting clauses of Article Two and Article Three, the Vesting Clause of Article One establishes the separation of powers among the three branches of the federal government. Section 2 of Article One addresses the House of Representatives, establishing that members of the House are elected every two years, with congressional seats apportioned to the states on the basis of population. Section 2 includes rules for the House of Representatives, including a provision stating that individuals qualified to vote in elections for the largest chamber of their state's legislature have the right to vote in elections for the House of Representatives. Section 3 addresses the Senate, establishing that the Senate consists of two senators from each state, with each senator serving a six-year term. Section 3 originally required that the state legislatures elect the members of the Senate, but the Seventeenth Amendment, ratified in 1913, provides for the direct election of senators. Section 3 lays out other rules for the Senate, including a provision that establishes the vice president of the United States as the president of the Senate.
