Right now: $1000 an ounce.
From 1789 to 1933, $20 an ounce. From 1933 to 1971, $35 an ounce—but Americans were forbidden to own monetary gold. In 1965, the silver was removed from the dime, quarter, half dollar, and silver dollar. In 1969, the government stopped honoring Silver Certificates (the Dollar Bill) and the Silver Certificate became the Federal Reserve Note, which is a Note for Nothing, which is like an I.O.U. that says ZERO on it. From 1971 to the present, we are on fiat money.
Earth’s first real civilization evaluated everything in terms of cattle. Gold was a commodity like any other commodity, and was counted out in cattle.