I was wondering if someone would know where I can research historical local gun laws.

For example, If I wanted to find out what the gun laws in New York City were like in 1945, where could I look?

FindLaw would be a good place to start.

That's as good a recommendation as one could make for the details.  I can tell you this, from hearing it on various discussion programs about 15 or 20 years ago.  There was a carry permit requirement ("Sullivan" law), and possibly a registration, though more of a formality than anything else.  Bottom line was that in 1945 if you wanted a gun (not carrying) it was quite easy.  In the same year, with a population of 8 million, there were less than 100 (I believe the figure was more like 45 or 50) murders with a gun.  Currently, it's in the couple thousand range.  And the laws are more restrictive.

I think some of the counters to the anti-gun people get too complicated.  The antis contradict themselves with their own comments.  (maybe this is where the original poster is going)

If more crime is logically (anti-everything, bizarro logic) addressed by more gun law, then how come there was less crime when by their own admission there were fewer gun laws?