The DJIA was more or less flat during WW2. Not sure where you've read that it was "great". During the middle of the war it was down 35-40%.
> Not sure where you've read that it was
Well.. I looked at the charts. The bottom was few months after Pearl Harbor and pretty much straight up after that. It certainly did much better after US joined than while it was staying out..
September 1939: DJIA was 152.54
May 1945: DJIA was 168.30
> The bottom was few months after Pearl Harbor and pretty much straight up after that
I mean, you've now picked the bottom of the market as your starting point (and not the start of WW2), so by definition it goes up after that.