9 most valuable U.S. coins
7. Saint-Goudens double eagle (ultra-high relief)
90% gold, 10% copper
This $20 double eagle gold piece — single gold pieces came in $10 denominations — was used mostly in international trade. The coin was designed, at President Theodore Roosevelt's behest, by the aforementioned Augustus Saint-Gaudens. The cast, which depicts Liberty holding a torch and an olive branch, was done in ultra-high relief, a rarity for U.S. coins. An even bigger rarity: When the silver eagle was first minted, it lacked the phrase 'In God We Trust' (again, at Roosevelt's behest). This triggered a public outcry, and Congress intervened, ordering the words to be added to the coin.
'Liberty' was based on Saint-Gaudens' figure of Victory, which is part of the William Tecumseh Sherman monument across from the Plaza Hotel in Manhattan. Subsuqent versions of the coin reigned in Saint-Gaudens' ultra-high relief, which was difficult to reproduce on a mass-edition coin. The world-reknowned sculptor apparently had difficulty downsizing.