5/19/1986 - the effective date of the otherwise upbeat "Firearm Owners Protection Act".  Section 922(o) outlawed the further production of machine guns for civilian ownership.

9/13/1994 - the effective date of the 1994 Violent Crime Control Act.  Section 922(r) gave us the 94 federal "semi-auto assault weapons" ban based on cosmetic features.

Other dates I'd like to know are:

1989 bush import ban
1989 prk roberti-roos aw ban
original brady bill

something 1934 1936? NFA
something 1968 GCO 1968 "sporting use" "none over 50 cal" "age limit" "and teh worst thing NO MAIL ORDER"