Who makes federal laws in the United States, and who can limit that authority? Congress, composed of the House of Representatives and the Senate, holds the lawmaking powers granted to it by the Constitution. The president participates through approval or veto, and courts can review laws in cases before them.
The federal lawmaking branch also represents different constituencies and checks other parts of government. Understanding what the legislative branch does requires looking at both chambers, their shared work, and the distinct responsibilities assigned to each.
What Is the Legislative Branch of the Federal Government?
What is the legislative branch? At the federal level it is Congress, the institution to which Article I of the Constitution gives the legislative powers granted by that document. Its two chambers must work together on ordinary legislation, even though they differ in size, terms of office, and representation.
The National Archives’ transcript of the Constitution supplies the text of Article I and the provisions governing the other branches. Later amendments changed some original arrangements; for example, the Seventeenth Amendment established direct election of senators. The structure of the legislative branch therefore reflects both the original Constitution and subsequent changes.
The House and Senate are federal institutions. Each state also has its own legislature, which makes state law within the powers available to that state. The federal legislative branch is Congress, while each state legislature is a separate lawmaking body. A federal congressional district and a state legislative district are different constituencies, and their representatives serve in different governments.
How the House and Senate Differ
The House has 435 voting representatives, with seats apportioned among states by population. Members serve two-year terms. Each state is guaranteed at least one representative. The House also includes nonvoting delegates and a resident commissioner from the District of Columbia and U.S. territories, whose roles differ from those of voting representatives.
The Senate has 100 members, two from each state, regardless of population. Senators serve six-year terms, with approximately one-third of seats scheduled for election every two years. This arrangement gives the chambers different relationships to population and elections. A bill that has substantial support in the House still needs agreement in the Senate to become law.
Committees in both chambers examine particular subjects, hold hearings, and consider proposals. They help members manage a large volume of work, but a committee’s approval does not itself make a bill law. Party leadership, chamber rules, and negotiations among members also affect which proposals receive a vote.
What Congress Can Do
What are the duties of the legislative branch? Congress writes and considers laws, decides how to exercise its constitutional powers, and scrutinizes the administration of federal programs. Article I lists powers including taxation, borrowing, regulation of interstate and foreign commerce, and declaring war. The Constitution also authorizes laws that are necessary and proper for carrying out federal powers.
The job of the legislative branch includes deciding whether and how public money is made available. Appropriations are laws authorizing withdrawals from the Treasury for specified purposes. Budget choices can influence executive agencies, although funding decisions remain subject to constitutional and statutory limits. Congress also investigates and conducts oversight through hearings, requests for information, and other means.
The authority to make federal laws is substantial, but it is not unlimited. The Constitution reserves some matters to the states or the people and protects individual rights against government action. Courts interpret those limits in actual disputes. Political disagreement about a law’s wisdom is distinct from a legal finding that it violates the Constitution.
How a Bill Becomes Law
A proposal generally must pass both chambers in identical form before it is presented to the president. If the House and Senate pass different versions, they must resolve their differences. The president may sign the measure or veto it; Congress can override a returned veto with the constitutionally required two-thirds vote in each chamber.
A bill can also become law without a signature if the president takes no action for the constitutional period, subject to the rule for an adjournment that prevents its return. The Congressional Research Service’s introduction to the legislative process explains this procedure and the stages that commonly precede final passage.
This process illustrates what the federal legislature is: a body that proposes and approves laws within a system of shared decision-making. Passing one chamber is an important step, but a proposal must clear the remaining constitutional stages before it has the force of federal law.
Checks Between and Within Branches
The chambers share lawmaking authority, but each has responsibilities the other does not. The House has the sole power to impeach federal officials, meaning it may formally bring charges. The Senate conducts impeachment trials; conviction requires a two-thirds vote of members present. Impeachment itself is not the same thing as conviction or removal.
The Senate also gives advice and consent on certain presidential nominations and treaties. Treaty consent requires two-thirds of senators present, while many nominations require a majority vote under Senate practice. The president negotiates treaties and makes nominations, illustrating how the Constitution divides these decisions between branches.
Congress can constrain executive action through legislation, appropriations, and oversight, while the president can veto legislation and executive agencies implement laws. Courts can decide whether a law violates the Constitution in a case properly before them. The constitutional role of Congress therefore depends both on its own choices and on its relationships with other institutions: each has tools to act, and each faces limits that make unilateral control difficult.