The 40% silver Kennedy half dollars were struck by the San Francisco Mint exclusively for three-coin 1976 silver proof sets released in honor of America's Bicentennial. In celebration, the Kennedy half dollar featured a unique reverse engraving of Independence Hall and dual 1776-1976 date. With your purchase, you'll also get a FREE 1976-S Kennedy half dollar copper-nickel proof that was once part of the year's clad six-coin proof set.