Following the assassinations of President John F. Kennedy, Attorney General and U.S. Senator Robert F. Kennedy and Dr. Martin Luther King, Jr., President Lyndon B. Johnson pushed for the passage of the Gun Control Act of 1968. The GCA repealed and replaced the FFA, updated Title II of the NFA to fix constitutional issues, added language about “destructive devices” (such as bombs, mines and grenades) and expanded the definition of “machine gun.”
Overall the bill banned importing guns that have “no sporting purpose,” imposed age restrictions for the purchase of handguns (gun owners had to be 21), prohibited felons, the mentally ill, and others from purchasing guns, required that all manufactured or imported guns have a serial number, and according to the ATF, imposed “stricter licensing and regulation on the firearms industry.”