The dollar used to be actual silver.
The dollar used to be redeemable for gold.
The dollar used to be printed on paper.
The dollar used to be backed by private debt.
The dollar used to be needed to buy oil internationally.
The dollar used to be used by foreign banks to settle debts (eurodollar)
The dollar used to be able to buy bitcoin
The dollar used to be used to pay off your loans
The dollar used to be used to pay taxes