The Second Amendment to the U.S. Constitution was sent to the states for ratification by the first U.S. Congress along with the nine other amendments that constitute what is known as the Bill of Rights. Ratified by the necessary three-fourths of the states on Dec. 15, 1791, the Second Amendment amended the Constitution to enshrine in law the individual right to keep and bear firearms.
The framers of the U.S. Constitution considered the Second Amendment a necessary protection for the American people from the possible threats posed to them by a standing military or an oppressive government, as the people experienced under British rule. It also was a means to ensure that the American people had the ability to defend themselves and their property.
Due to the mention of a militia in the text of the Second Amendment, there have been numerous lawsuits and much public debate regarding whether or not the amendment protects an individual right to own firearms or if it instead only protects a collective right to own firearms as part of a militia. In a 19th-century case, the U.S. Supreme Court ruled that the Second Amendment did not prohibit individual states from adopting legislation that regulated the ability of citizens to possess firearms. In the landmark District of Columbia v. Heller decision handed down in 2008, the U.S. Supreme Court ruled that the Second Amendment does in fact grant an individual the right to own firearms for purposes traditionally deemed lawful. The court also held that certain regulations, such as a ban against handguns, violated the constitutional rights of the American people.