This is one of 3 restrike dollars made using the reverse of the famous 1804 original dollar.
It is unclear when these were actually struck or why. Some people believe these were struck in the 1850s or earlier while others believe they were struck in the 1870s.
Those who believe in an earlier, pre-1858 date mention the use of the 1804 original reverse. If this reverse was still around, why make more 1804 dollars and use a different reverse die ?
Those who believe in the latter theory point to the fact that they were struck on what appear to be trade dollar planchets, were unknown until John Haseltine displayed a set of 1801, 1802 and 1803 dollars in early 1876 and also mention the description by S.H. Chapman in the Lyman sale catalog: "Struck between 1870 and 1876. When I entered this business in May 1876, these dollars of 1801, 2, and 3, were being offered by mint officials now deceased, but very few have ever appeared and I believe they are very rare. I have only known of about three sets".
Only 2 examples are known. One is ex Haseltine 1/79, Cleaney, Mougey, Lyman, Granberg, Brand (journal #92338), Boyd - illustrated and the other is ex Newcomer, Col Green, Roe, Neil, Carter, French and was struck on a defective planchet.
Additional information can be found in "Silver Dollars and Trade Dollars of the United States" by Dave Bowers and Mark Borckardt.
Image courtesy of www.coinsite.com