The Second Amendment (Amendment II) to the United States Constitution protects the right of the people to keep and bear arms and was adopted on December 15, 1791, as part of the first ten amendments contained in the Bill of Rights. The Supreme Court of the United States has ruled that the right belongs to individuals, while also ruling that the right is not unlimited and does not prohibit all regulation of either firearms or similar devices. State and local governments are limited to the same extent as the federal government from infringing this right, per the incorporation of the Bill of Rights.
The Second Amendment was based partially on the right to keep and bear arms in English common law and was influenced by the English Bill of Rights of 1689. Sir William Blackstone described this right as an auxiliary right, supporting the natural rights of self-defense and resistance to oppression, and the civic duty to act in concert in defense of the state.
In United States v. Cruikshank (1876), the Supreme Court of the United States ruled that, “The right to bear arms is not granted by the Constitution; neither is it in any manner dependent upon that instrument for its existence” and limited the scope of the Second Amendment’s protections to the federal government. In United States v. Miller (1939), the Supreme Court ruled that the Second Amendment did not protect weapon types not having a “reasonable relationship to the preservation or efficiency of a well regulated militia”.
In the twenty-first century, the amendment has been subjected to renewed academic inquiry and judicial interest. In District of Columbia v. Heller (2008), the Supreme Court handed down a landmark decision that held the amendment protects an individual right to possess and carry firearms. In McDonald v. Chicago (2010), the Court clarified its earlier decisions that limited the amendment’s impact to a restriction on the federal government, expressly holding that the Due Process Clause of the Fourteenth Amendment incorporates the Second Amendment against state and local governments. In Caetano v. Massachusetts (2016), the Supreme Court reiterated its earlier rulings that “the Second Amendment extends, prima facie, to all instruments that constitute bearable arms, even those that were not in existence at the time of the founding” and that its protection is not limited to “only those weapons useful in warfare”.
Despite these decisions, the debate between various organizations regarding gun control and gun rights continues.