During the Cold War, Nuclear weapons proliferated. Now, our government is still striving to reduce the number of Nuclear Weapons. That is not within the aspect of this site. However, given our CLOSE ties to Hanford, Washington, the following Youtube video IS.
Note that the Mark 3 weapon was the "Fatman" bomb, used in Japan.
This neat little Youtube video gives an instructional look at our Nuclear Weapons of that era. It is a montage of a couple training films from that era, with a look at all of the ways to employ nuclear weapons. It will keep you busy for 17 minutes, so be warned. Still, if you are interested in such things, you will find it educational!
Note, especially, the referral to Nike Missile sites at about 15 1/2 minutes in. I have been to a decommissioned Nike site. There isn't much to see. It's impressive to see them in their former glory!
So, here, have a look and a listen, maybe you'll learn something, or maybe you will see how close we came to a totally different world. Either way, it is a good idea to see how it was.