The 20 hardest questions on the 2025 citizenship test, and how to remember them

Passing the civics test does not require knowing everything. It requires knowing most things well, and not being surprised by the few questions that work differently from the rest. Those are the questions this guide covers.

How we chose these 20

USCIS does not publish which questions applicants miss most, so this is not an official list. We chose these questions by looking at what makes an answer hard to give under pressure, based on the official 2025 question list:

• the question asks why, so you must explain a reason, not name a fact;
• the answer is an exact number or date that is easy to mix up;
• the answer depends on an amendment or a legal idea;
• the question needs two, three or five answers at once; or
• the answer is an unfamiliar name or phrase, sometimes in Latin.

Each question below links to its own page with a full explanation and a memory tip.

1. The “why” questions

The 2025 test added many questions that ask for a reason. You cannot answer them with a single name, but the official answers are still short. Learn the key phrase for each.

1. Q26. Why do U.S. representatives serve shorter terms than U.S. senators?
   U.S. representatives serve shorter terms than senators to more closely follow public opinion.
2. Q28. Why does each state have two senators?
   Each state has two senators to give equal representation, especially for small states. This was the Great Compromise.
3. Q49. Why is the Electoral College important?
   The Electoral College is important because it decides who is elected president.
4. Q84. Why were the Federalist Papers important?
   The Federalist Papers were important because they helped people understand the Constitution and supported passing it.
5. Q101. Why did the United States enter World War I?
   The United States entered World War I because Germany attacked U.S. ships, and to support the Allied Powers against the Central Powers.
6. Q110. Why did the United States enter the Korean War?
   The United States entered the Korean War to stop the spread of communism.
7. Q114. Why did the United States enter the Persian Gulf War?
   The United States entered the Persian Gulf War to force the Iraqi military from Kuwait.

Memory trick: make a “because” card for each one. Front: “Why two senators?” Back: “Equal representation.” Say the back aloud until the phrase comes out on its own.

2. Exact numbers and dates

These answers are a single number or date, which makes them easy to confuse with other numbers on the test.

1. Q54. How many Supreme Court justices are usually needed to decide a case?
   Usually five (5) Supreme Court justices are needed to decide a case.
2. Q79. When was the Declaration of Independence adopted?
   The Declaration of Independence was adopted on July 4, 1776.
3. Q98. When did all men get the right to vote?
   All men got the right to vote after the Civil War, during Reconstruction, with the 15th Amendment in 1870.
4. Q104. When did the Great Depression start?
   The Great Depression started with the Great Crash, the stock market crash of 1929.

Memory trick: put the dates in order on one line: 1776 (Declaration), 1787 (Constitution), 1870 (15th Amendment, all men vote), 1920 (19th Amendment, women vote), 1929 (Great Depression starts). Seeing them as a timeline keeps them apart. For the Supreme Court: 9 seats, but usually 5 justices decide a case, because 5 is a majority of 9.

3. Amendments and legal ideas

Amendment questions are hard because the amendments have numbers instead of names, and several of them deal with similar topics.

1. Q60. What is the purpose of the 10th Amendment?
   The 10th Amendment states that powers not given to the federal government belong to the states or to the people.
2. Q63. There are four amendments to the U.S. Constitution about who can vote. Describe one of them.
   One of the four voting amendments says citizens eighteen (18) and older can vote. Others ended the poll tax, gave women the vote and protected the vote regardless of race.
3. Q97. What amendment says all persons born or naturalized in the United States, and subject to the jurisdiction thereof, are U.S. citizens?
   The 14th Amendment says all persons born or naturalized in the United States, and subject to its jurisdiction, are U.S. citizens.

Memory trick: link each number to one word. 10th: “states” (powers not given to the federal government belong to the states or the people). 14th: “born” (citizenship by birth). 15th, 19th, 24th and 26th: “vote” (race, women, no poll tax, age 18). You only need to describe one voting amendment, so learn the one you remember best: “citizens 18 and older can vote” (26th) is the simplest.

4. Questions that need more than one answer

These questions ask for two or five items. If you give one fewer, the answer is wrong, even if every item you gave was correct.

1. Q10. Name two important ideas from the Declaration of Independence and the U.S. Constitution.
   Two important ideas are equality and liberty. Others include natural rights, limited government and self-government.
2. Q67. Name two promises that new citizens make in the Oath of Allegiance.
   In the Oath of Allegiance, new citizens promise to give up loyalty to other countries and to defend the Constitution, among other promises.
3. Q81. There were 13 original states. Name five.
   Five of the 13 original states are New York, New Jersey, Pennsylvania, Virginia and Georgia.

Memory trick: for the 13 original states, learn five that are easy for you to say and always say the same five. Many people use New York, New Jersey, Pennsylvania, Virginia and Georgia. For two-part questions, learn a fixed pair, such as “equality and liberty”, and practise saying both every time.

5. Documents, writers and Latin

Some answers are names or phrases that most people never use in daily life.

1. Q14. Many documents influenced the U.S. Constitution. Name one.
   Documents that influenced the Constitution include the Declaration of Independence, the Articles of Confederation and the Federalist Papers.
2. Q83. The Federalist Papers supported the passage of the U.S. Constitution. Name one of the writers.
   The writers of the Federalist Papers were James Madison, Alexander Hamilton and John Jay, writing as “Publius.”
3. Q124. The Nation’s first motto was “E Pluribus Unum.” What does that mean?
   “E Pluribus Unum” means “Out of many, one.”

Memory trick: for the Federalist Papers, remember the pen name “Publius” and one writer you already know from other questions, such as James Madison, who is also the “Father of the Constitution”. For “E Pluribus Unum”, connect the phrase to the idea of the United States itself: many states, one nation.

How to study the hard ones

1. Give them their own deck. Put these 20 on separate flash cards and review them every day, in addition to your normal study.
2. Say the answers aloud. Multi-part and “why” answers are easier to recall when you have said them many times.
3. Mix them into practice tests. Our free practice test picks questions at random from all 128, just like the officer. Note which hard questions you still miss.
4. Do not let one hard question shake you. You need 12 of 20, not 20 of 20. If you miss one, take a breath; the next question may be easy. Our guide to staying calm at the test can help.

For the full study plan, read how to pass the US citizenship test, and remember to check the answers that change shortly before your interview.