I'm assuming you're referring to one of these @potty dollar 1878? Regardless, these notes were canceled by the U.S. Government, plus several boxes of these were thrown out onto the street during a fire at the Treasury building in 1935. This is why these notes are relatively common and are often worth less than face value.
If you find one of these, however, do not cash it in at the bank, because they tend to be worth FAR MORE than face value.
The earlier gold certificates that are worth less than face value were redeemed, cancelled and thrown out in 1935 as noted above. Those gold certificates only circulated betwixt banks.
