The 2026 S Silver Proof Set by the U.S. Mint commemorates the 250th anniversary of the mint's establishment. This set includes a 25 cent silver coin, struck with a proof finish in San Francisco. The coin has a fineness of 0.999 silver and is part of the Semiquincentennial series. The set is a special presale edition, making it a valuable addition to any coin collector's assortment.