Most important U.S. laws to know

When you come to live in the United States, you will not know all the laws and regulations. There are many thousands of laws! Every state has its own laws, too. Here are some U.S. laws that are useful to know so you do not break the law by mistake. This page covers laws related to children; driving; discrimination; taxes; bribery; marriage, sex, and incest; behavior in public; drugs and alcohol; animals and hunting; fighting and violence; online use; other crimes; trespass; Military Selective Service; and proof of U.S. residency.

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  • Your children must go to school from the age of 6 to 16.
  • You must not hit, neglect or abuse your children.
  • Your children must use safety seats in the car.
  • Some states have laws to say you cannot leave your children alone until they reach a certain age.
  • You can read about parenting laws in the USA.


  • You must get car insurance and registration for your car and carry it in the car.
  • Everyone must have a driver’s license to drive.
  • Drivers can turn right when the stoplight is red if it is safe to do so and if nobody is crossing the street, unless there is a sign or red light telling you not to turn.
  • You must wear a seatbelt in a moving car (unless you are an adult in the state of New Hampshire).
  • Do not pass a school bus in either direction when its red lights are flashing! Just stop until the bus turns off its flashing lights.
  • Pull over to let emergency vehicles go by if they have flashing lights or sirens.
  • You can read about how to drive in the USA.


  • You may refuse service to someone who is offensive, but you may not refuse service to people because of their race, sex, religion or where they come from.
  • You can learn more about anti-discrimination laws that protect LGBTQ people and working women.


  • If you earn income and live in the United States, you must file a tax return every year and pay taxes to the United States government. In some places, you will pay state and local government taxes too.
  • You can learn how to pay taxes in the USA.


  • It is illegal to bribe or offer bribes to police and other officials in the United States.
  • It is illegal to accept bribes.

Marriage, sex, and incest

  • It is against the law to have sex with a member of your family who is not your spouse.
  • You are not allowed to be married to more than one person at the same time.
  • You are not allowed to hit or beat your wife or other family members.
  • It is against the law to force a person to have sex with you even if you are married to them.
  • Nobody, even your parents, can force you to marry someone if you do not want to get married.
  • You can get a divorce from your spouse even if your spouse does not agree.
  • It is a crime to marry someone just to get US citizenship. You can be jailed or fined a lot of money.
  • It is not against the law to be a homosexual or lesbian, and it is legal to marry someone of the same sex.

Behavior in public

  • You may be fined for crossing the road except at a crosswalk!
  • You are not allowed to drop litter in a public place.
  • Drinking alcohol and (in some places) smoking are against the law in the street.
  • Indecent behavior (including nakedness, urinating, prostitution or hiring a prostitute) is illegal.

Drugs and alcohol

  • The legal drinking age in the United States is 21.
  • You must not give alcohol to anyone under the age of 21 or let them drink alcohol in your care. (There are exceptions in some states for parents, who may allow their children to drink in their care.)
  • It is illegal to take drugs or to sell or provide illegal drugs (which are called “controlled substances” in the law).
  • The use and sale of marijuana is allowed in some states under some conditions.

Animals and hunting

  • Hunters must have a hunting license to kill wild animals.
  • You can only kill wild animals in certain seasons and with certain weapons.
  • It is illegal to kill cats and dogs for food.
  • In most states, animal cruelty or neglect is against the law. This means overworking, neglecting, starving, torturing or beating animals. You can read more about wild animals, hunting and fishing and about animal and pet rules in the USA.

Fighting and violence

  • Violence to another person is against the law.
  • Some fighting is called “disorderly conduct” or “mutual combat.” Other fighting or attacking someone is called “assault.” Even threatening someone can be an assault, which is a serious crime.

Online use

  • Downloading and using content (such as music, movies, books) without permission is illegal and can be considered Intellectual Property Theft.
  • Producing, keeping, downloading, and viewing child pornography is a crime.
  • Arranging  a face-to-face meeting with a minor is illegal.
  • Phishing is a crime. Phishing is when someone impersonates a business or a person to try to obtain personal information.
  • Cyberstalking and online stalking are crimes.
  • Online drug trafficking, buying and selling drugs online is illegal.
  • Hacking online accounts, accessing personal information, logging into emails, and social media accounts without authorization can potentially send you to jail.

Other crimes

  • It is a crime to cheat people or to steal from people or stores.
  • It is a crime to sell illegal drugs or guns.


Americans are very protective of their homes and property. You cannot be on or in someone’s property without their permission.

Military Selective Service

If you are a male between the ages of 18 and 26 and living in the United States, you must register for selective service in the armed forces.

Proof of U.S. residency

  • If you are a resident or permanent resident but not a citizen, you must carry proof of your resident status with you (your papers or your Green Card).
  • You must also notify USCIS when you change your address.

There are many US laws, but you also have many rights! Use our resources to find information about your rights as a resident or citizen.

The information about US laws on this page comes from the US government and other trusted sources. It is intended for guidance and is updated as often as possible. USAHello does not give legal advice, nor are any of our materials intended to be taken as legal advice. If you are looking for a free or low-cost lawyer or legal help, we can help you find free and low-cost legal services.