The United States finally took gold out of complete circulation in 1934 with The Gold Reserve Act being enacted. It happened mainly because of The Great Depression in the 1930's and Roosevelt changed the valuation of gold to $35.00 per ounce. From there we went to paper money(dollars) that were promised to be good for "one-dollars worth of gold". We still see silver certificates today (the strange green colored dollars that say "silver certificate") and the government does have to still honor those since some escaped being pulled. After all certificates issuing gold were pulled because the price of gold would fluctuate and people would abuse the system, the government implemented the dollars you see today which have the face-value printed and supposedly have the gold to back them up.