My grandfather joined and served for four years. His whole family moved to CA from Arkansas the day after Pearl Harbor and he and his 3 brothers all joined. They each picked a different branch.
Amazingly all four brothers made it home alive. One of them was supposed to be at D Day but broke his leg in a training exercise in England 2 days before. He felt guilty about that the rest of his life.
Truly the greatest generation. I can't even imagine if we tried to draft today' group of 18-20 year olds to send them to war. Bung of man bun wearing faggots would have a conniption.