The Saint-Gaudens $20 gold was and still is thought by many to be the finest design for a coin of commerce since the high art of ancient Greece. It's story is one of art
versus ego, foiled sabotage, and the strict intervention by the most powerful man in the country for its numismatic debut.
In 1905, renown sculptor Augustus Saint-Gaudens was asked by his personal friend, President Theodore Roosevelt to submit some designs for the gold $10 and $20 coins. Roosevelt felt the "unbearable dullness of design" of America's coinage needed a face lift, and wanted to emulate the magnificence of the numismatic works of Ancient Greece. The President was impressed by Saint-Gaudens' skill after having him design his inaugural medal. The results of the ailing St. Gaudens were magnificent, but not feasible as a coin of commerce. The gifted Augustus' unfamiliarity with the coining process resulted in the initial examples requiring nine powerful blows from the mint's hydraulic press to bring out all of the design detail. Once placed into circulation, bankers complained that the high relief $20 coins wouldn't stack properly.
From the beginning, however, a jealous opposition from the mint, headed by Chief Engraver Charles E. Barber made the execution of the design a tedious, frustrating, and nearly impossible endeavor for Saint-Gaudens, and later his assistant Henry Hering. Barber's stonewalling created tremendous delays in the designing and minting process. At one point, President Roosevelt stepped in, ignoring Barber's objections, and ordered him to "begin the new issue even if it takes you all day to strike one piece!"
After the death by cancer of Augustus Saint-Gaudens in 1907, the dies were modified several times, Barber added his own changes, and the coinage was struck. Although still America's most beautiful design, the coin was an emasculated shell of the greatness it had been. Mintage continued until 1933, when FDR took the United States off the gold standard and made the ownership and production of gold coins illegal, after which most of the 1912-33 coinage was subsequently melted.
Several variations of the coin were struck. The initial prototypes, known as Ultra High Relief (27 minted) and Regular High Relief (11,250+ minted) had their date expressed in Roman numerals (MCMVII) and possessed a deeply engraved, medallic quality. Toward the end of 1907, a Barber-designed, low relief example with its date in ordinary numerals was released for circulation. Finally, between 1908 and 1933, an adjustment was made to the design in that the motto "In God We Trust" was added to the reverse. The deeply religious President Roosevelt objected to its inclusion on the basis of coins bearing the name of God might possibly be used for sinister purposes (gambling, buying weaponry, etc.) Congress and the public, however, thought that those pressing for its continued exclusion were atheists (disbelievers of God), anarchists (disbelievers in government), or Bolsheviks (Communists), hence its addition to the design.
References: The U.S. Mint and Coinage - Taxay; Walter Breen's Complete Encyclopedia of U.S. and Colonial Coins - Breen