Gun laws in the United States regulate the sale, possession, and use of firearms and ammunition. State laws (and the laws of Washington, D.C. and the U.S. territories) vary considerably, and are independent of existing federal firearms laws, although they are sometimes broader or more limited in scope than the federal laws.
State level laws vary significantly in their form, content, and level of restriction. Forty-four states have a provision in their state constitutions similar to the Second Amendment to the U.S. Constitution, which protects the right to keep and bear arms. The exceptions are California, Iowa, Maryland, Minnesota, New Jersey, and New York. In New York, however, the statutory civil rights laws contain a provision virtually identical to the Second Amendment. Additionally, the U.S. Supreme Court held in McDonald v. Chicago that the protections of the Second Amendment to keep and bear arms for self-defense in one's home apply against state governments and their political subdivisions.
Firearm owners are subject to the firearm laws of the state they are in, and not exclusively their state of residence. Reciprocity between states exists in certain situations, such as with regard to concealed carry permits. These are recognized on a state-by-state basis. For example, Idaho recognizes an Oregon permit, but Oregon does not recognize an Idaho permit. Florida issues a license to carry both concealed weapons and firearms, but others license only the concealed carry of firearms. Some states do not recognize out-of-state permits to carry a firearm at all, so it is important to understand the laws of each state when traveling with a handgun.