Hold on, I've got a dollar bill... no, wait, it's a Five Cents one
http://www.antiquemoney.com/fractional-currency-value-and-price-guide/
So many weird things went on in the Civil War. Apprehensive citizens were hoarding coins and metal was in demand anyway, so the government issued paper money worth five cents each. This was better than the increasing habit of using stamps as money. Come to think of it, not too long ago, there were magazine ads where you were offered the choice of mailing in stamps rather than coins. Amateur fanzines did this a lot, but then much of their overhead was mailing costs anyway.
Of course, trudging through the grocery store, we may well feel that your dollar IS only worth five cents at this point. I know the pain.