The SS Central America is the richest US ship wreck ever discovered. There are books about it and many online references which are worth following up and these are only a few.
Many of the Assayers who made the ingots were known but none of their ingots ever discovered so the ones discovered in the shipwreck are unique andmany of the coins are worth over $1,000,000 each as they are unique or so rare.
The guy who first got them did a runner and still will not tell where he has hidden 500 coins - may not seem much BUT at a possible $1,000,000 a piece maybe they were worth hiding - he is in jail for not surrendering them.
If you want a coin then some are available
If you want to read about it then the books are worth reading but especially; -