The U.S. Constitution divides the federal government into three branches. The legislative branch, called Congress, is responsible for making the nation's laws. The other two branches are the executive branch , headed by the president, and the judicial branch , headed by the Supreme Court .
Most of the provisions concerning Congress appear in Article I of the Constitution. It begins, “All legislative powers herein granted shall be vested in a Congress of the United States, which shall consist of a Senate and House of Representatives.” This means Congress is a bicameral legislature, one with two chambers.
When the Constitution was written in 1787, large states would not agree to a legislature with equal representation for each state, and small states would not agree to a legislature with representation based on population. The solution was to create a bicameral Congress. Each state has two members, or senators, in the Senate, giving the states equal representation there. Membership in the House of Representatives, however, is based on population, giving larger states more power there than smaller states. Both the Senate and the House of Representatives must agree for Congress to enact a law.
The Constitution dictates elections for the full House every two years. To become a representative, a person must be at least twenty-five years old, a U.S. citizen for at least seven years, and an inhabitant of the
state he or she is to represent. The number of representatives a state gets in the House is based on population. Initially, slaves counted as only three-fifths of a person for this calculation, but that was changed by the Fourteenth Amendment after slavery became illegal throughout America.
The Constitution originally called for the selection of senators by state legislatures. The Seventeenth Amendment changed this method to popular elections. Senators serve six-year terms, with the elections staggered so that one-third of the seats are up for election every two years. To become a senator, a person must be at least thirty years old, a U.S. citizen for at least nine years, and an inhabitant of the state he or she is to represent. The vice president of the United States serves as president of the Senate and has the power to cast a vote on legislation and other matters only when the Senate is equally divided.
Powers of Congress
To pass a bill (a proposal for a new or revised law), both chambers of Congress must agree by simple majorities. If they do and the president signs it, the bill becomes a law. If the president vetoes (rejects) the bill, it goes back to Congress for reconsideration. A vetoed bill only becomes law if both chambers vote in favor of it by two-thirds majorities.
The Constitution contains a section on the powers of Congress. The powers include those to collect taxes; provide for the common defense and general welfare of the country; borrow money; regulate commerce with Native Americans, foreign nations, and between the states; establish rules on citizenship and bankruptcies; coin and regulate money; establish a postal service; protect inventions, writings, and discoveries; establish courts under the Supreme Court; make laws regarding the seas and international law; declare war; raise and regulate armies and navies; provide for national service by state militias; make laws for the land area occupied by the federal government; and make all laws that are necessary and proper for wielding its other powers and those of the rest of the federal government.
The original Consitution contained specific limitations on the power of Congress. It forbade Congress from banning the importation of slaves before 1808. Congress may not suspend the writ of habeas corpus, a method for freeing a person who is imprisoned illegally, except in times of rebellion or invasion. Congress may not criminalize a person's past conduct or impose criminal sanctions on a person without a trial. After the adoption of the original Constitution, many amendments placed further limits on the power of Congress, notably the first ten amendments in the Bill of Rights adopted in 1791.