Funny you should mention it, during the time that the Alaska pipeline was being built, there were so many gold diggers marrying the really highly paid workers and divorcing them just to get their money, that Alaska began issuing marriage licenses with an expiration period, if you couldn't get along you just let it lapse, and if you so desired you could renew the license or get a non-expiring one. Just a bit of trivia.
Marriage poses little threat to government compared to an armed citizenry, so it would be quite natural for the government to want to be able to regulate the firearms that could be used against it. OK, I'll admit that I'm a cynic, but I find it akin to the fox watching the henhouse.
Do dogs and hunting and fishing and driving a car pose threats to the government? You have to have licenses for all of that as well.
Interesting and weird story about Alaska.