The Coinage Act of 1849, or the Gold Coinage Act (Act of March 3, 1849, An Act to authorize the Coinage of Gold Dollars and Double Eagles, 30th Congress, Sess. 2, Chap. 109, 9 Stat. 397), was an act of the United States Congress which allowed for the minting of two new denominations of gold coins, the gold dollar and the gold $20 or double eagle. It further defined the variances which were permissible in United States gold coinage. The act contains four (4) sections.
This was enacted largely due to the California Gold Rush.
References
Coinage Act of 1849 Wikipedia(Text) CC BY-SA