Why did the USA go semi-auto when others did not?

[bacarnal]

One point that seems to be missing on this thread is that during a good portion of this time frame was a world wide depression. Leading up to it was, on the allies side, let's not think about war and hope it goes away and on the German/Austrian side, having to pay economically crushing war reparations. The US had started to get the mentality to have a battlefield semi-auto with the Mark I Pederson Device. Despite detractors of a new caliber (MacCarther for one, who was worried about large numbers of .30 cal ammo left over from WW I) and others worried about ammunition expenditures by the common Dog Face or Jar Head, the common Joe LEARNED about firepower in the Trenches, being on the receiving end, and came to embrace it. And those common soldiers became the politicians that would drive that, despite the established and entrenched Generals who "knew" how to win a war. So despite a long and painful teething, we finally ended up with a workable and robust infantry weapon where both our allies and opponents couldn't find the money or mentality. Just several reasons among many that I think we ended up with the M1.