Lobbying in the United States describes paid activity in which special interest groups hire well-connected professional advocates, often lawyers, to argue for specific legislation in decision-making bodies such as the United States Congress. It is often perceived negatively by journalists and the American public; critics consider it to be a form of bribery, influence peddling, and/or extortion. Lobbying is subject to complex rules which, if not followed, can lead to penalties including jail. Lobbying has been interpreted by court rulings as free speech protected by the First Amendment to the U.S. Constitution. Since the 1970s, the numbers of lobbyists and the size of lobbying budgets has grown and become the focus of criticism of American governance.

The United States Congress is the legislature of the federal government of the United States. It is bicameral, composed of a lower body, the House of Representatives, and an upper body, the Senate. It meets in the U.S. Capitol in Washington, D.C. Senators and representatives are chosen through direct election, though vacancies in the Senate may be filled by a governor's appointment. Congress has 535 voting members: 100 senators and 435 representatives. The U.S. vice president has a vote in the Senate only when senators are evenly divided. The House of Representatives has six non-voting members.