Responsibilities and duties
The U.S. Constitution clearly enumerates the responsibilities of Congress. They include regulating domestic and international trade, declaring war and maintaining and supporting the military.
Congressmen's duties vary according to their stature and party affiliation. Both of the two major political parties have a leader in each House (called either the majority leader or the minority leader, depending on which party has more members in the House). Party leaders are responsible for maintaining diplomatic relations with one another and with other branches of the government.
Each house also has many committees that focus on a particular responsibility. Some examples include energy, veterans' affairs, housing and foreign relations. Some committees have broad responsibilities, such as the Committee on Commerce, Science and Transportation.
One of the most common duties of a congressman is act as a conduit between the federal government and the local authorities and residents of the areas they represent. A local police force, for example, might ask a congressman for help receiving money or other services from the Department of Justice. A local unit of a veterans' organization, such as the American Legion, might likewise ask a congressman for support in obtaining something from the Veterans Administration.