This is the famous 1866 silver set using the without motto reverse of the prior year. It consists of the quarter dollar J536/P600, half dollar J538/P602 and silver dollar J540/P605.
These pieces de caprice are believed to have been deliberately struck for Robert Coulton Davis sometime in the later 1860s or early 1870s. The set was later a part of the Woodin, Newcomer, Boyd and Farouk collections where it was broken up and then reunited in the Willis Dupont collection. The set was stolen along with many other rare coins in 1967. The half and the quarter were recovered in December 1999 and the dollar in early 2004. The set was on display at the ANA until, according to the February 20, 2015 article in Coin World by Paul Gilkes, the Dupont family donated the coins to the Smithsonian in November 2014.
A duplicate dollar ex Chapman, Brand (journal id #20657) is also known. There are questions regarding the pedigrees of the 2 dollars as to which is the Farouk coin.
Photos courtesy of the ANA and American Numismatic Rarities.