From what Valve has said, TF2 takes place in the late fifties, early sixties-- the James Bond era.
Soldier tried to enlist in WW2 when he was 14, and promptly failed every psyche exam the US army used during their HIGHEST time of recruitment.
Nevertheless, he traveled there himself and waged a one-man war against the Nazi's, earning 14 medals (which he designed and built himjself) He then stopped killing nazi's and returned home when he got word that the war had ended-- in 1945...

Medic left Germany for unknown reasons after he crashed the Prime Minister's wedding and stole the catering van. That's how he got Archimedes.

That bit of nerdiness out of the way.

This was awesome! Thanks!