The Congress of the United States is the legislative branch of the federal government. Comprised of the House of Representatives and the Senate, the Congress brings together 435 representatives of the people, 100 Senators from 50 states, and 5 delegates from the territories of the United States -- an assembly of 540 to make the laws that govern the nation.
The Congress, like most of the world's legislatures, is bicameral, that is, composed of two chambers. The Senate is composed of two Senators from each state, who are elected to serve a term of six years. The Members of the House of Representatives, who each represent approximately 650,000 people, are elected for two-year terms. The number of representatives from each state is determined by population, but each state is entitled to at least one representative.
The two-chamber design of the U.S. Congress is consistent with the basic principle of government embraced by the framers of our Constitution -- that government must be divided into units which share power with one another, providing an inherent check against tyranny. The division of the Congress into two chambers emanates from this principle.
The two chambers are considered equal, although they differ from one another in many respects. In terms of legislative power, both must concur in and adopt identical legislation in order for it to be enacted into law. The Senate has sometimes been called the upper body and the House, the lower body. These are popular misnomers, arising from the simple fact that when Congress first met in New York City, the Senate chamber was located on the floor above the House. The two legislative bodies are equal, but different, and each is granted exclusive powers by the U.S. Constitution.
For an extensive historical discussion about the origins of bicameralism, see the final report of the Joint Committee on the Organization of Congress, issued in December 1993. Visit http://democrats.rules.house.gov/archives/jcoc2.htm.