gun control, government limitation of the purchase and ownership of firearms. The availability of guns is controlled by nations and localities throughout the world. In the United States the "right of the people to keep and bear arms" is guaranteed by the Constitution, but has been variously interpreted through the years. Since the late 1930s federal judicial and law enforcement officials generally held that the right exists mainly in the context of the maintenance of a state militia, but in 2002 the Justice Dept., under Attorney General John Ashcroft, indicated that it interpreted the amendment as more broadly supporting the rights of individuals to possess and bear firearms. Such an interpretation was upheld by a 2008 Supreme Court decision that nonetheless did not challenge the government's right to place some limitations on the ownership and possession of firearms.

Some U.S. states and localities have enacted strict licensing and other control measures, and federal legislation (1968) prohibited the sale of rifles by mail. Gun control has continued to be widely debated, however, and has often been opposed, notably by the National Rifle Association (NRA). Increasing gun-related crimes together with citizen pressure propelled congressional passage (1993) of the "Brady bill" (named for James Brady, the press secretary seriously wounded in the 1981 assassination attempt on President Ronald Reagan) after years of controversy. It required a minimum of a five-day waiting period and background check before a handgun purchase. Parts of the bill were challenged in court and in 1997 the Supreme Court invalidated its background-check provision. The 1994 Crime Bill outlawed the manufacture, sale, and possession of military-style assault weapons, but it expired in 2004. In 1999, following a rash of shootings at U.S. schools, further gun-control legislation was passed by the Senate but was voted down by the House of Representatives. Attempts by localities (through legislation) and individuals (through lawsuits) to pursue gun control through the courts by permitting or bringing negligence suits against a gun manufacturer or dealer when a weapon it made or sold is used in a crime led many states and, in 2005, Congress to pass laws limiting such suits.