The Three Branches of the U.S. Government

Updated: October 30, 2026

The U.S. government has three branches: the legislative branch (Congress) makes laws, the executive branch (the president) carries out laws, and the judicial branch (the courts) explains and reviews laws. The Constitution splits power this way so that one part does not become too powerful, a system known as separation of powers and checks and balances.

Why three branches?

The founders had just fought a war against a king they saw as having too much power. When they wrote the Constitution in 1787, they deliberately divided the national government so that no single person or group could control everything. Each branch has its own job, and each can limit the others.

The 2025 civics test asks this directly: "There are three branches of government. Why?" Accepted answers are so one part does not become too powerful, checks and balances, and separation of powers.

The legislative branch - Congress

What it is: the U.S. Congress, made up of the Senate and the House of Representatives.

Main job: writing laws.

Key facts for the test:

100 senators, two per state, serving six-year terms
435 voting members of the House, serving two-year terms
Powers include writing laws, declaring war, and making the federal budget
The House is led by the Speaker of the House (Mike Johnson, as of the USCIS test updates page in 2026)

The Constitution describes Congress first, in Article I, which reflects how central lawmaking was to the founders. For details, see how Congress works.

The executive branch - the President

What it is: the President, the Vice President, the Cabinet, and the federal departments and agencies.

Main job: enforcing and carrying out laws.

Key facts for the test:

The president is elected for four years and can serve only two terms because of the 22nd Amendment
The president is Commander in Chief of the military
The president signs bills into law and vetoes bills
The president appoints federal judges
The Cabinet advises the president
If the president can no longer serve, the Vice President becomes president

The 2025 test lists many Cabinet-level positions as acceptable answers, including the Attorney General, Secretary of State, Secretary of the Treasury, Secretary of Homeland Security, and the Vice President. Two of them are enough. As of 2026, the President is Donald J. Trump and the Vice President is JD Vance, but always confirm on the USCIS test updates page before your interview.

The judicial branch - the courts

What it is: the Supreme Court and the other federal courts.

Main job: reviewing and explaining laws and resolving disputes.

Key facts for the test:

The Supreme Court is the highest court in the United States
It has nine seats, and five justices are usually needed to decide a case
Justices serve for life, so they can be independent of politics
The Chief Justice, as of 2026, is John Roberts

Accepted answers for "What does the judicial branch do?" are reviews laws, explains laws, resolves disputes about the law, and decides if a law goes against the Constitution. See the Supreme Court explained.

Checks and balances in practice

Checks and balances are easier to remember with examples:

Congress checks the president: it can override a veto with a two-thirds vote in both chambers, the Senate confirms many appointments and approves treaties, and Congress controls the budget.
The president checks Congress: the president can veto bills.
The president checks the courts: the president appoints federal judges.
The Senate checks the courts: it must confirm those judges.
The courts check both: they can decide that a law or an executive action goes against the Constitution.
Congress can remove officials: the House can impeach and the Senate holds the trial.

A simple way to picture it: a bill passes Congress, the President signs it, and the courts can later decide whether it fits the Constitution.

How the branches connect to your state

The same three-part design exists in every state: a state legislature, a governor, and state courts. The 2025 test asks about your state's governor and capital, while the federal government has its own powers, like printing money and making treaties. Learn the split in federal vs. state powers.

Quick self-test

Try answering these out loud before checking:

What part of the federal government writes laws?
The President of the United States is in charge of which branch?
Who vetoes bills?
What is the highest court in the United States?
Name one power of the president.

Answers: Congress (the legislative branch); the executive branch; the President; the Supreme Court; signs bills into law, vetoes bills, enforces laws, Commander in Chief, chief diplomat, or appoints federal judges.

Questions 20, 44, and 52 on this topic are marked with an asterisk on the USCIS list, so they also appear on the 65/20 list. For the full list, see the civics questions, and an app like Civio can quiz you on them in random order until they stick.

Frequently asked questions

What are the three branches of government?

Legislative, executive, and judicial. USCIS also accepts "Congress, president, and the courts."

Why does the U.S. have three branches of government?

So one part does not become too powerful. The idea is called separation of powers, and the branches limit each other through checks and balances.

Which branch is the most powerful?

None is meant to be. The Constitution gives each branch ways to limit the others, so they must work together to govern.

Who is in charge of the executive branch?

The President of the United States. The executive branch also includes the Vice President, the Cabinet, and federal departments and agencies.

What does the judicial branch do?

It reviews and explains laws, resolves disputes about the law, and decides whether a law goes against the Constitution.

Prepare for the civics test with Civio: every official question from the 2025 USCIS civics test, Exam Mode with your state's questions, and spaced repetition.

Informational article, not legal advice. Civio is not affiliated with USCIS or any government agency; always check current requirements at uscis.gov.