Federal laws in the United States are made by Congress. The House of Representatives and the Senate write and pass statutes, the President signs them into law or vetoes them, federal agencies issue regulations that fill in the operational details, and federal courts can strike down any statute or regulation that violates the Constitution. Those four actors, working within the roles the Constitution assigns them, produce what we call federal law.
Congress Holds the Lawmaking Power
Article I, Section 1 of the Constitution places all federal lawmaking power in Congress through what’s known as the Vesting Clause.1Legal Information Institute (LII). Article I Section 1 – Overview of the Legislative Vesting Clause That one sentence is the reason the President cannot write statutes by executive order and the Supreme Court cannot legislate from the bench. Congress has the monopoly on turning policy into binding federal law.
Article I, Section 8 then lists what Congress is allowed to legislate about. These enumerated powers cover taxing and spending, regulating commerce between states and with foreign countries, maintaining the military, coining money, establishing post offices, and about two dozen other subjects.2Legal Information Institute. Article I Section 8 – Enumerated Powers If a topic doesn’t fit one of those categories or get pulled in by the “necessary and proper” clause at the end of Section 8, Congress technically has no business regulating it. The commerce power has been read broadly enough to reach most national policy areas, but the boundary still matters and courts still enforce it.
Congress also controls the money. Article I, Section 9 says no funds can leave the Treasury unless Congress has approved the expenditure through an appropriations law.3Office of the Law Revision Counsel. Constitution of the United States of America Even when a program exists by statute and an agency has been told to run it, the money still has to be specifically allocated before a dollar can be spent. That power of the purse is one of Congress’s strongest checks on the executive branch.
How a Bill Moves Through Congress
The House of Representatives has 435 voting members, apportioned to the states by population. The Senate has 100 members, two from every state regardless of size. A statute has to pass both chambers in identical form before it can become law.
Only a sitting representative or senator can introduce a bill. Once introduced, it goes to a committee with jurisdiction over the subject, where members and staff hold hearings, hear from experts and stakeholders, and revise the text through a process called markup.4house.gov. The Legislative Process Most bills die here. The committee stage is where legislators decide whether a proposal is worth the full chamber’s time, and the vast majority never make it out.
A bill that clears committee goes to the full chamber for debate and a vote. The House and Senate often pass different versions of the same bill, and when that happens, a conference committee negotiates a compromise text that both chambers then vote on again.4house.gov. The Legislative Process
The Senate Filibuster
The Senate has a procedural wrinkle the House doesn’t. Under Senate rules, any senator can extend debate on a bill indefinitely unless 60 senators vote to invoke cloture and cut off discussion.5U.S. Senate. About Voting A bill technically needs only 51 votes to pass the Senate, but it often needs 60 just to reach a final vote. The filibuster isn’t in the Constitution; it’s a Senate rule. But it’s the reason many bills with majority support still fail.
The President Signs, Vetoes, or Lets It Sit
Once both chambers pass identical text and the bill is formally enrolled, it goes to the President, who has ten days (not counting Sundays) to act on it.6Library of Congress. Article I Section 7 – Constitution Annotated Three things can happen:
- The President signs the bill and it becomes law.
- The President vetoes the bill and sends it back with written objections. Congress can override the veto if two-thirds of both the House and Senate vote to do so, and the bill then becomes law without the President’s signature.7Legal Information Institute (LII). Article I of the Constitution
- The President does nothing. If Congress is still in session when the ten days expire, the bill becomes law automatically. If Congress has adjourned during that window, the bill dies. This is a pocket veto, and Congress has no opportunity to override it.6Library of Congress. Article I Section 7 – Constitution Annotated
The two-thirds override threshold is deliberately high, and overrides are rare in practice. The threat of a veto often shapes legislation long before it reaches the President’s desk.
Executive Orders Are Not Federal Laws
Presidents issue executive orders often, and media coverage sometimes treats them as equivalent to legislation. They aren’t. An executive order directs federal agencies and employees on how to carry out existing law. It cannot create new legal obligations for private citizens or spend money Congress hasn’t appropriated. The authority comes from Article II, which vests executive power in the President and requires the President to “take Care that the Laws be faithfully executed.”8Legal Information Institute (LII). Overview of the Take Care Clause
Every executive order has to be grounded in either the Constitution or a statute Congress has already passed. A president cannot create or abolish a federal department, impose a new tax, or appropriate funds by executive action alone. And because executive orders rest on presidential authority rather than legislative consensus, a later president can revoke or replace them. Federal statutes can only be changed through the full legislative process.
Agencies Write the Regulations That Fill In the Details
Congress often writes laws in broad terms and delegates the technical details to federal agencies. The Clean Air Act directs the Environmental Protection Agency to set air quality standards, for instance, but Congress doesn’t specify the parts-per-million threshold for each pollutant. The agency fills in those blanks through rulemaking, and the resulting regulations carry the force of law.
Rulemaking is governed by the Administrative Procedure Act, codified at 5 U.S.C. §§ 551–559.9Office of the Law Revision Counsel. 5 U.S. Code 553 – Rule Making Under the APA’s informal rulemaking process, an agency publishes a notice of its proposed rule in the Federal Register, explains the legal authority behind it, and gives the public a chance to submit written comments. After reviewing those comments, the agency publishes a final rule along with its reasoning. Notice-and-comment is the public’s main window to influence a regulation before it takes effect.
Final rules are compiled in the Code of Federal Regulations, organized by subject area.10eCFR. 1 CFR Chapter I – Administrative Committee of the Federal Register If you want to know what the law actually requires in a regulated industry, the CFR is often where the binding details live.
Courts Can Strike Down Statutes and Regulations
Federal courts act as a check on both Congress and the executive branch. Since the Supreme Court’s 1803 decision in Marbury v. Madison, courts have exercised judicial review, meaning they can declare a federal statute unconstitutional and void it entirely.11Justia. Marbury v. Madison, 5 U.S. 137 (1803) This power isn’t written explicitly in the Constitution; it’s treated as implied by Article III and Article VI.3Office of the Law Revision Counsel. Constitution of the United States of America
Courts also review agency regulations. Under 5 U.S.C. § 706, a court can set aside agency action that exceeds the agency’s statutory authority or that is “arbitrary, capricious, an abuse of discretion, or otherwise not in accordance with law.”12Office of the Law Revision Counsel. 5 USC Ch. 7 – Judicial Review For decades, courts gave agencies significant leeway in interpreting ambiguous statutes under a doctrine called Chevron deference. That changed in 2024, when the Supreme Court overturned Chevron in Loper Bright Enterprises v. Raimondo and held that courts must exercise their own independent judgment about what a statute means rather than deferring to the agency’s reading.13Supreme Court of the United States. Loper Bright Enterprises v. Raimondo (2024) Agency regulations now face tougher scrutiny in court, and legal challenges to federal rules are more likely to succeed than they were before.
Federal Law Overrides Conflicting State Law
Article VI declares that federal law is “the supreme Law of the Land” and that state judges are bound by it regardless of anything in state constitutions or statutes to the contrary.3Office of the Law Revision Counsel. Constitution of the United States of America When a valid federal statute directly conflicts with a state law, the federal law wins. This principle, called preemption, comes up often in immigration, banking regulation, and drug policy, where state and federal rules sometimes point in different directions.
Preemption isn’t automatic. In areas traditionally regulated by states, federal law generally doesn’t override state law unless Congress clearly intended it to. But when Congress does intend to occupy a field, it can sweep aside state regulations entirely, even popular ones.
Where to Read Federal Law for Yourself
Federal statutes live in the United States Code, which organizes all general and permanent federal laws into 54 subject-matter titles.14Office of the Law Revision Counsel. Detailed Guide to the United States Code Content and Features Title 26 covers the Internal Revenue Code, Title 18 covers federal crimes, and so on. The full text is searchable and free at uscode.house.gov, maintained by the Office of the Law Revision Counsel.15Office of the Law Revision Counsel. The United States Code
Agency regulations live in the Code of Federal Regulations, available online through the Electronic Code of Federal Regulations at ecfr.gov. The eCFR is updated continuously, making it more current than the official print edition, which is only revised once a year.10eCFR. 1 CFR Chapter I – Administrative Committee of the Federal Register To figure out exactly what federal law requires in a specific area, you’ll usually need both: the statute from the U.S. Code for the broad rule, and the regulation from the CFR for the operational details.