Interesting reference in the final paragraph of this article (especially considering that this post is entitled "back in saner times") - Montana passed a law requiring full gun registration in 1918. A lot of the history in this post seems to begin at 1934 and much is after 1968. I guess the 1968 laws are what moved the needle for most advocates...?

http://www.acslaw.org/acsblog/gun-laws-are-as-old-as-gun-ownership