How Congress Works: Complete Guide

Structure of Congress

The United States Congress is a bicameral legislature, meaning it consists of two chambers: the House of Representatives and the Senate. This structure was created at the Constitutional Convention of 1787 as a compromise between large and small states. Large states wanted representation based on population; small states wanted equal representation. The result was a House apportioned by population and a Senate with two members per state.

The 535 total members of Congress represent more than 330 million Americans. Each of the 435 House districts represents approximately 760,000 people. Senate seats represent entire states — Delaware's two senators represent about 1 million people, while California's two senators represent 40 million. This disparity in the Senate's representation is built into the Constitution and cannot be changed even by constitutional amendment, per Article V.

Congress is organized into numbered sessions corresponding to two-year cycles. The 119th Congress, for instance, began in January 2025 and runs through January 2027. Each session within the Congress begins in January of odd-numbered years following House elections.

How a Bill Becomes Law

The path from bill introduction to presidential signature involves numerous steps, any of which can halt the process. First, a member introduces a bill by submitting it to the chamber clerk. The bill is assigned a number (H.R. for House bills, S. for Senate bills) and referred to the appropriate committee.

Committee consideration is where most bills die. Committees hold hearings to gather testimony, mark up (amend) legislation, and vote on whether to send it to the full chamber. Roughly 10,000 bills are introduced each Congress; fewer than 500 typically become law. Committee chairs control the agenda and can simply decline to schedule hearings on bills they oppose.

If a committee approves a bill, it goes to the floor of the full chamber for debate and voting. The House and Senate have different rules governing floor debate. The House uses a Rules Committee to set parameters for each bill's debate; the Senate generally operates by unanimous consent agreements or through procedural votes.

For a bill to become law, both chambers must pass identical text. When the House and Senate pass different versions, they go to a conference committee that negotiates a compromise. Both chambers then vote on the final conference report — no further amendments are permitted at this stage.

After Congress passes a bill, the president has ten days to sign or veto it. A signed bill becomes law. A vetoed bill returns to Congress, where a two-thirds vote in both chambers can override the veto. If the president neither signs nor vetoes, the bill becomes law automatically after ten days — unless Congress has adjourned, in which case the bill is "pocket vetoed."

Congressional Committees

Committees are where the actual work of Congress happens. Both chambers have standing committees with permanent jurisdiction over broad policy areas — Armed Services, Judiciary, Finance, Appropriations, and others. Select committees are temporary bodies created for specific investigations or purposes. Joint committees include members of both chambers.

The most powerful committees in terms of legislative influence are the Appropriations Committees, which control annual government spending; the Ways and Means Committee (House) and Finance Committee (Senate), which handle tax and revenue legislation; and the Rules Committee (House), which controls the terms of floor debate on legislation.

Subcommittees handle more specific subject areas within each standing committee's jurisdiction. Much of the detailed legislative work — holding hearings, drafting bill language, hearing testimony from agency officials — happens at the subcommittee level before a bill moves to the full committee.

Congressional Leadership

The Speaker of the House is the chamber's presiding officer and the most powerful figure in the House. The Speaker is elected by the full House at the start of each Congress. In practice, the Speaker is always the leader of the majority party. The Speaker controls the legislative agenda, assigns bills to committees, and manages floor proceedings.

The Senate's presiding officer is formally the Vice President of the United States, though the VP rarely appears in the chamber. The Senate's day-to-day operations are managed by the President pro tempore (the most senior member of the majority party) and, practically speaking, by the Senate Majority Leader. The Majority Leader controls the Senate floor schedule and is the most powerful position in the chamber.

Majority and Minority Whips in both chambers are responsible for counting votes, ensuring members are present for key votes, and communicating leadership priorities to rank-and-file members. The whip operation is essential for managing close legislative votes.

The Senate Filibuster

The Senate filibuster is a procedural rule that effectively requires 60 votes to advance most legislation in the 100-member chamber. To end debate and proceed to a vote — a process called cloture — 60 senators must agree. If a party has fewer than 60 senators, the minority can block legislation by refusing to vote for cloture.

The filibuster does not apply to all Senate business. Budget reconciliation legislation requires only a simple majority of 51 votes, which is why major budget and tax bills often move through reconciliation. Presidential nominees require only 51 votes after rule changes in 2013 (executive and lower court nominees) and 2017 (Supreme Court nominees).

The filibuster has become increasingly central to Senate dysfunction as partisan polarization has made bipartisan agreement on legislation rare. Critics argue it gives the minority too much power to obstruct the majority's agenda. Defenders argue it forces compromise and protects minority rights from majoritarian excess.

Confirmation Hearings

The Senate confirms presidential nominees for executive branch positions, federal judgeships including Supreme Court justices, and numerous other roles. The confirmation process typically begins with a committee hearing where the nominee testifies and senators question them. The committee then votes on whether to recommend the nominee to the full Senate.

Supreme Court confirmation hearings have become highly visible political events. Nominees typically decline to preview how they would rule on specific cases — a practice dating to the Ginsburg hearings in 1993 — and instead discuss judicial philosophy at a general level. Critics argue this makes hearings less informative; supporters argue it preserves judicial independence.

The Impeachment Process

Impeachment is the constitutional process for removing federal officeholders — the president, vice president, federal judges, and other civil officers. The House holds the sole power to impeach; a simple majority is required. Impeachment is analogous to an indictment — it does not remove the official but brings formal charges.

The Senate then holds an impeachment trial. For presidential impeachments, the Chief Justice presides. Conviction requires a two-thirds vote of senators present. If convicted, the official is removed from office. The Senate may also vote to bar the convicted official from holding future federal office, which requires only a simple majority.

Three presidents have been impeached by the House — Andrew Johnson (1868), Bill Clinton (1998), and Donald Trump (2019 and 2021). None were convicted by the Senate. Richard Nixon resigned before the House voted on articles of impeachment in 1974.

Contacting Your Representatives

Every American has one House representative and two senators. To find your representatives, visit congress.gov or house.gov and enter your zip code. Congressional offices maintain constituent services staff who can assist with issues related to federal agencies, veterans benefits, immigration cases, and other matters.

Phone calls to congressional offices are tracked and reported to members as constituent sentiment. Calls are generally considered more impactful than emails, which are often routed through form-letter responses. Personal meetings with members or their district staff — especially during congressional recesses when members return to their home districts — can be particularly effective.

Frequently Asked Questions