Commercial plane travel started following World War II. The advent of the jet plane provided a quick way to travel internationally, and helped establish the U.S. dollar as a world standard currency. Currency has evolved as well. Notes denominated in more than $100 were eliminated from circulation in 1969. More recently, new anti-counterfeiting features have been incorporated in the $100, $50, and $20 bills. While American currency is still the world standard, electronic payments systems may reduce the need for cash and spark further changes in the evolution of American currency.