Gold Double Eagles are $20 face value coins which were issued by the United States between 1849 and 1933. These are the largest denomination regular issue US coin.
The term "double eagle" was specifically used in the authorizing legislation from Congress passed on March 3, 1849. $10 face value coins were already being produced and were referred to as "gold eagles." Thus the new coin with twice the value and gold content was referred to as the "double eagle."
The first double eagle was dated in 1849, the same year as the California Gold Rush. Although the coin carried this date, it was actually minted one year earlier in 1850. The first double eagle produced now resides in the Smithsonian Institute in Washington, DC.
There were two regular series of Double Eagles produced. They were the Liberty Head series and Saint Gaudens series.
The Liberty Head series was produced between 1849 and 1907. These coins had a weight of 33.436 grams with a standard composition of 90% gold and 10% copper. The net gold weight was .96750 ounces. The coins had a diameter of 34 millimeters and were minted at the Philadelphia, Carson City, Denver, New Orleans, and San Francisco Mints.
The Saint Gaudens series was produced between 1907 and 1933. The coins take their name from the designer, Augustus Saint Gaudens. They share the same specifications as the prior series and were minted at the Philadelphia, Denver, and San Francisco Mints. The Saint Gaudens Double Eagle is widely considered to be the most beautiful U.S. coin. The same design is currently used on the American Gold Eagle Bullion Coins.