In 1854, San Francisco businessmen sent a petition to Secretary of the Treasury James Guthrie for a $50 coin to be struck because no banknotes of any denomination circulated in California.

[1] United States Mint engraver George T. Morgan made sketches of a possible design for a $100 coin in 1876, should the half union ever be a success.

Around 2005, Morgan's original sketches were discovered and published so the numismatic community could see what could have been.

Private mints have since struck fantasy pieces of Morgan's design for collectors, in both silver and gold.

[2] The $100 denomination has been produced by the US Mint since 1997 in the form of the American Platinum Eagle bullion coin.