The largest denomination of United States coin authorized by the Mint Act of 1792 was the eagle, or ten-dollar piece. The large amount of bullion being brought east after the discovery of gold in California in the 1840s caused Congress to consider new denominations of gold coinage. The gold dollar and double eagle were the result. After considerable infighting at the Philadelphia Mint, Chief Engraver James B. Longacre designed the double eagle, and it began to be issued for commerce in 1850. Only one 1849 double eagle is known to survive and it rests in the National Numismatic Collection at the Smithsonian.