A US Constituitional dollar was equal to this much silver:
Grains__Ounces__Troy Ounces
371.25___0.84______0.77
In 1913 a ONE unit Federal Reserve Note was equal to a ONE DOLLAR Silver Certificate.
Grains__Ounces__Troy Ounces
18.563___0.042_____0.0385
In 1923 a ONE unit Federal Reserve Note was equal to 5% of it's 1913 value.