I think that we have discovered why congress has become so crooked.
I am sure serving gave some of them some needed character.
here are some graphs...
http://www.pbs.org/newshour/rundown/by-the-numbers-veterans-in-congress/
As to the numbers, it's worth knowing who was in combat and who was a file clerk back home.
In any case, it's not just character. When kids were drafted, along with the risks they learned how to read, they learned new skills (many of them marketable), they became fit, learned self-discipline, and there were outstanding education benefits through the GI Bill. There is also the fact that nearly every family had someone in the military or knew someone who did. The war was a part of one's life. Nowadays nearly everyone is disconnected from it and, for the most part, don't really care whether we spend the rest of our lives at war or not. And so it goes on. And on.