The|Coinologist.

New Orleans, LA has been a major port for the United States since the American Revolution.  It only made sense that the New Orleans Mint be open, as a branch mint of the United States Mint.  It was operated from 1838 to 1861 and from 1879 to 1909. These coins were struck with an “O” mint mark.  The American Civil War saw a change of hands at the mint, which made this facility the only mint to produce both U.S. and Confederate coins, which are highly collectible to this day.  The Confederacy ran out of  bullion in in  April 1861, and the building was used for quartering soldiers.  It wasn’t until after the Reconstruction Era that it reopened for business. During its years of operation, it produced over 427 million gold and silver coins of nearly every American denomination, with a total face value of over $307 million.  Since 1981 it has served as a branch of the Louisiana State Museum. Damaged by Hurricane Katrina in 2005, after over two years of closure for repair and renovation, the museum reopened in October 2007.  The New Orleans Mint has been designated a National Historic Landmark, and is currently the oldest surviving structure to have served as a U.S. Mint.

1907 Postcard of the New Orleans Mint.

The status of the 1856-O double eagle as the rarest New Orleans twenty, from a paltry mintage of 2,250 pieces, was established as long ago.  This coin sold for $1.4+ million at a Heritage Auction at the Long Beach Coin, Stamp, & Collectibles Expo.