This is a 2017 struck from a Private Issue Barber proposed design 1877 $50 Half Union certified by NGC as GEM Proof Denver ANA Show Releases.
In 2017, the Smithsonian issued this proof silver medal as a reproduction of a famous U.S. coin that was proposed but never released for circulation. This 1 oz. proof silver medal features the Half-Union design that was intended to be used for a circulating $50 gold coin. Mintage of this special medal was limited to just 2,500 pieces.
The obverse and reverse designs on this medal were originally created by William Barber, fifth Chief Engraver of the U.S. Mint and father of Charles E. Barber. The date is displayed on the obverse along with a detailed portrait of Liberty. The reverse features a very detailed bald eagle design. The lower portion shows the silver content and face value. Inscriptions stating the medal's release at the 2017 Denver ANA show can be found near the middle of the design.