The Manhattan project was an absolutely unbelievable accomplishment. Keep in mind that one of the first things they did was to
invent new elements (plutonium for one). Most employees arrived in Los Alamos with no idea of why they were there, and many didn't leave until after the war was over.
Imagine, you're sitting in your office one day and some Army officer comes by and tells you that they want you to work for them on a project that will end the war. Furthermore, you'll have to relocate your family to an unspecified place to do whatever it is they want you to do - but you can't know what that is yet either. I mean, who's going agree to that? But it will end the war so you go.
It really is a fascinating story, and if one is so inclined, the book "The Making of the Atomic Bomb" by Richard Rhodes covers things nicely.
Don