When the California gold rush began in 1848, the U.S. Mint had difficulty handling the significant influx of new gold being mined, and it was determined that a more substantial gold coin would be necessary to accommodate the increase. So, with the Act of March 3, 1849, Congress authorized the minting of the largest denomination of regular currency in U.S. history: the gold Double Eagle. Valued at$20, the Double Eagle contained .9675 ounces of pure gold and featured a Liberty Head designed by James Longacre on the obverse and a heraldic eagle design on the reverse. As the first year of production, no pieces were struck for circulation in 1849, but two pattern strikes are known to exist: one is held in the Smithsonian Institute, while the other's location is unknown. With such a limited number struck, the 1849 Double Eagle is a true rarity.