Some of that is just that inflation fundamentally changed when we floated the dollar in 1971. We now purposely try to inflate our currency 2% every year. Before then there was inflation and deflation, but not a single trend. A dollar in 1800 was worth essentially the same as it was in 1933--though there were long periods where it was less and long periods it was more.
Interesting. Didn't know that. I'm more familiar with the UKP which only goes down in value :(
USD only does down since 1971 too. I think the UKP was on the gold/silver standard until recently too.