The assassination of John F. Kennedy, who was killed by a mail-order gun that belonged to Lee Harvey Oswald, inspired this major revision to federal gun laws. The subsequent assasinations of Martin Luther King and presidential candidate Robert Kennedy fueled its quick passage. License requirements were expanded to include more dealers, and more detailed record keeping was expected of them; handgun sales over state lines were restricted; the list of persons dealers could not sell to grew to include those convicted of felonies (with some exceptions), those found mentally incompetent, drug users and more. The act also defined persons who were banned from possessing firearms.
The key element of this bill outlawed mail order sales of rifles and shotguns; Up until this law, mail order consumers only had to sign a statement that they were over 21 years of age for a handgun (18 for rifle or shotgun); it also detailed more persons who were banned from possessing certain guns, including drug users, and further restricted shotgun and rifles sales.