The Liberty series of gold coins spans four coin denominations and two different Chief Engravers of the U.S. Mint. This includes Christian Gobrecht's $2.50 quarter eagle, $5 half eagle, and $10 gold eagle, as well as James Longacre's $20 double eagle. All four were struck from 90% pure gold.
Although they were replaced by the dramatic engravings of Augustus Saint-Gaudens (for the $10 and $20 coins) and Bella Lyon Pratt (for the quarter eagles and half eagles), the style of the Liberty gold coins is considered by many the classic standard of U.S. coin designs. This is attested by the fact that the Liberty series of gold coins ran from 1838-1907 without major design alterations.
The Liberty Head design is often called the Coronet Head type, referring to the elegant crown upon Lady Liberty's head inscribed with "LIBERTY." Each of the four designs in the Liberty series feature thirteen stars around the rim of the obverse and a version of the heraldic eagle on the reverse. Prior to 1866, the Liberty gold coins lacked the religious motto, "IN GOD WE TRUST." The motto was added in the wake of the Civil War and the Lincoln assassination. Check out Gainesville Coins' selection of Liberty gold coins.