A double eagle is a gold coin of the United States with a denomination of $20. (Its gold content of 0.9675 troy oz (30.0926 grams) was worth $20 at the 1849 official price of $20.67/oz.) The coins are made from a 90% gold (0.900 fine = 21.6 kt) and 10% copper alloy and have a total weight of 1.0750 troy ounces (33.4362 grams).
The "eagle", "half eagle", and "quarter eagle" were specifically given these names in the Act of Congress that originally authorized them ("An act establishing a mint, and regulating coins of the United States", section 9, April 2, 1792). Likewise, the double eagle was specifically created as such by name in the Coinage Act of 1849 ("An act to authorize the coinage of gold dollars and double eagles", title and section 1, March 3, 1849). Since the $20 gold piece had twice the value of the eagle, these coins were designated "double eagles". Prior to the 1849 double eagle, the largest denominated US coin was the $10 gold eagle, which was first produced in 1795, two years after the first U.S. mint opened.
The production of the first double eagle coincided with the 1849 California Gold Rush. In that year, the mint produced two pieces in proof. The first now resides in the Smithsonian Institution in Washington, D.C.. The second was presented to Treasury Secretary William M. Meredith and was later sold as part of his estate—the present location of this coin remains unknown.
In 1904, President Theodore Roosevelt sought to beautify American coinage, and proposed Augustus Saint-Gaudens as an artist capable of the task. Although the sculptor had poor experiences with the Mint and its chief engraver, Charles E. Barber, Saint-Gaudens accepted Roosevelt's call. The work was subject to considerable delays, due to Saint-Gaudens's declining health and difficulties because of the high relief of his design. Saint-Gaudens died in 1907, after designing the eagle and double eagle, but before the designs were finalized for production. The new coin became known as the Saint-Gaudens double eagle.
Regular production continued until 1933, when the official price of gold was changed to $35/oz by the Gold Reserve Act. The 1933 double eagle is among the most valuable of U.S. coins, with the sole example – the King Farouk specimen, which was purchased by King Farouk of Egypt in 1944 – currently known to be in private hands selling in 2002 for $7,590,020. Twelve other specimens exist, two of which are held in the National Numismatic Collection and the United States Bullion Depository at Fort Knox.