If the public actually knew what it does today they might lose faith in the US dollar. Actually that's all that is behind it, and nearly all other currencies today.
Until I was a teenager, every dollar bill was a silver certificate anyone could exchange at the mint or Federal Reserve Bank for an ounce of silver. Other denominations had been backed by specific quantities of gold until FDR stole our gold when my parents were teenagers. Johnson stole our silver. Actually in both cases it was congress who stole it to pay for FDR/Johnson sponsored programs, and to permit currency inflation. Before that they could only borrow to cover their deficit spending.
The gold and silver never belonged to the Federal Reserve or the government. It always belonged to the citizens. We just used government mints to certify content. They typically even put imprints on the edge of gold coins because lots of people would "shave" gold coins to steal small bits of it from each coin.
I believe Federal Reserve Banks were originally just places to keep gold and silver coins for local banks to draw upon. Eventually, gold was held mainly at heavily armed Fort Knox and mostly just gold and silver certificates (precious metal backed paper currency) was stocked at the Federal Reserve Banks.
I don't particularly advocate "hard" currency, but it does prevent politicians and bureaucrats from watering down our currency whenever they think we won't hand them more taxes. Currency inflation is too often used as an underhanded way of taxing us by sneaking wealth directly out of our wallets.
