Congress of untied state is the legislative branch of the federal government that is introduced in 1789. Congress of United States is composed of two houses. These houses are named as Senate and House of representative.
The members of the Senate were chosen by the state legislatures until 1913. After that, direct election were used to elect representatives. A senator's age must at least 30 years. Senators of US congress must be U.S. citizen of not less than nine years standing. A senator must be a resident of the state in which he or she is elected. The Senate is supervised by the vice president of the United States. The President has as no part in Senate planning he just vote only in case of a tie. In the absence of President his duties are performed by a president pro tempore, elected by the Senate. The senate members are chosen for six years terms.

Member of House of representative are chosen for 2 years term. Representative age must be 25 years or more. He must be US citizen of at least seven year standing. Just like Senator Representative must also be the resident of the state in which they are elected.

Laws of the United States are made by the Congress. The job of making law is done by the standing committees of Senate and House of Representative. Beside that there are special committees in each house as well as joint committees which help in Law making. Both the Senate and House of representative have the equal rights in legislation. But revenue bills must work out in the House of Representatives. After preparation of bills it must be pass by each house. And then they must get signed by the President within the 10 days otherwise they become Law automatically. If President refuse bill then in that case it may become Law only if re passage by a two-thirds majority in each house. Congress annual meetings on regular bases are required by the constitution. Only the House of Representatives have the right to finger point the president or other federal officers. Senate just has the authority to try formal accusation. The Senate must approve all agreements by a two-thirds vote. They must also confirm important presidential appointments to office which includes confirmation of cabinet members, judges of federal courts, and high-ranking officers of the armed forces. Because of this responsibility of the Senate and because it is the smaller body and its members enjoy longer terms of office and almost unlimited debate, it is regarded as the more commanding of the two houses. Congress, as a whole played an important role during the time period of reconstruction after the civil war.