How the US Government Works
A clear, nonpartisan tour of the system: the Constitution, the three branches, how they check each other, how an idea becomes a law, and how elections work, including the 2026 midterms. Then walk a bill through Congress yourself.
The Constitution
The US Constitution is the country's supreme law. It was written in Philadelphia in 1787, took effect in 1789, and is the oldest written national constitution still in use. It does three big jobs:
- Sets up the government: three branches with separate powers (Articles I, II and III).
- Limits that government: it can only use the powers the Constitution gives it.
- Protects rights: the first ten amendments, the Bill of Rights (ratified 1791), protect freedoms like speech, religion, press, assembly, and a fair trial.
It opens with “We the People,” the idea that the government's power comes from the people.
Changing it is hard on purpose
There have been 27 amendments. The usual path: two-thirds of both the House and Senate propose an amendment, then three-fourths of the states (38 of 50) ratify it. (The Constitution also allows a convention called by two-thirds of the states, but that route has never been used.)
The three branches
Congress makes laws
House of Representatives: 435 voting members, seats divided by state population, 2-year terms. Senate: 100 members, 2 per state, 6-year terms. Congress also controls federal spending and can declare war.
The President carries out laws
The President (4-year term, limit of two elected terms) leads the executive branch, the Vice President, the Cabinet and federal agencies, and is commander in chief of the military.
Courts interpret laws
The Supreme Court (nine justices today) and lower federal courts decide cases about what laws and the Constitution mean. Federal judges serve during “good behavior,” which in practice means for life.
| Office | Minimum age | Term |
|---|---|---|
| Representative | 25 | 2 years |
| Senator | 30 | 6 years |
| President | 35 | 4 years |
| Federal judge | None set | Good behavior |
Checks and balances
The framers worried about any one person or group gaining too much power. So each branch has ways to limit the others. This is called checks and balances, and it often means change happens slowly, which is part of the design.
| Branch | Checks on others |
|---|---|
| Legislative | Override a veto (two-thirds of both chambers) · control spending · impeach and remove officials · Senate confirms judges and top officials · Senate approves treaties (two-thirds) |
| Executive | Veto bills · nominate judges · grant pardons for federal crimes · enforce (carry out) laws |
| Judicial | Declare laws or executive actions unconstitutional (judicial review, established in Marbury v. Madison, 1803) |
For each power, pick the branch that holds it.
How a bill becomes a law
- Introduced. Only a member of Congress can introduce a bill, in the House or the Senate. (Tax bills must start in the House.) Anyone can suggest an idea to their member.
- Committee. The bill goes to a committee of members who specialize in that topic. They may hold hearings, make changes (“markup”), and vote. Most bills never make it out of committee.
- Floor vote. The full chamber debates and votes. A simple majority passes it. In the Senate, ending debate on most bills takes 60 votes (cloture), so the filibuster can block a bill that has majority support.
- Other chamber. The bill goes through the same process in the other chamber. Both must pass the exact same text. If they differ, they negotiate (sometimes in a conference committee) and both vote again.
- The President. The President can sign it (it becomes law), veto it, or do nothing. If the President does nothing for 10 days (not counting Sundays) while Congress is in session, it becomes law. If Congress has adjourned in those 10 days, it's a pocket veto and the bill dies.
- Veto override. Congress can override a veto with a two-thirds vote in both the House and Senate. Overrides are rare.
Federal vs state government
The US uses federalism: power is shared between the national (federal) government and the 50 states. Each state has its own constitution, governor, legislature and courts. Local governments (counties, cities, school districts) get their powers from the state.
Nationwide matters
Printing money, the military and declaring war, foreign treaties, interstate and international trade, immigration and naturalization, the postal service.
Most daily life
Running elections, driver's licenses, most criminal law, public schools, marriage law, local police and fire, and zoning.
- Shared powers: both levels can tax, borrow, make and enforce laws, and run courts.
- 10th Amendment: powers not given to the federal government, nor denied to the states, are reserved to the states or the people.
- Supremacy Clause: when a valid federal law conflicts with a state law, the federal law wins.
Elections, including the 2026 midterms
Federal general elections are held on the Tuesday after the first Monday in November in even-numbered years.
- Presidential elections (every 4 years) use the Electoral College. Each state gets electors equal to its House seats plus its two senators; DC gets 3. That's 538 in all, and a candidate needs 270 to win. Most states give all their electors to the statewide winner; Maine and Nebraska split theirs by congressional district.
- Midterm elections fall halfway through a presidential term. All 435 House seats are up, plus about a third of the Senate (senators' terms are staggered). Many states also elect governors, legislators and local officials, and vote on ballot measures.
The 2026 midterms are on Tuesday, November 3, 2026. Every House seat and roughly a third of Senate seats are on the ballot, along with many state and local races.
How to be ready to vote
- Check you're eligible. US citizen, meet your state's residency rules, and 18 by Election Day.
- Register or check your registration at vote.gov. Deadlines vary by state; some allow same-day registration, and North Dakota has no voter registration.
- Learn your options. Early voting and mail-in (absentee) voting rules and deadlines vary by state. Your state or local election office has the official details.
- Find your polling place and what to bring, since ID rules also vary by state.
FAQCommon questions
What's the difference between Congress and the House?
Congress is both chambers together: the House of Representatives and the Senate. “Congressman” or “congresswoman” usually refers to a House member, though senators are members of Congress too.
Can the Supreme Court make laws?
No. It decides cases. But its rulings on what the Constitution or a law means apply nationwide and can strike down laws, so its decisions have a large effect.
Can the President declare war?
The Constitution gives Congress the power to declare war. The President is commander in chief and directs the military. How these powers fit together has been debated for a long time.
Why does a state's number of House seats change?
Seats are reapportioned among the states after each census, every 10 years, based on population. The total stays at 435.
How do I find who represents me?
Search by your address on the official House and Senate websites (house.gov and senate.gov), or usa.gov's elected officials page.