U.S. Mint Proof - Six sets - 1971, 1986 (3), 1997, Lincoln Bicentennial The U.S. Mint Proof sets from 1971 to 1997, including the Lincoln Bicentennial set, are composed of silver coins struck in proof condition at the San Francisco Mint. These sets are made in the United States and showcase the craftsmanship and history of American coinage. Each set includes a variety of coins with different designs and themes, making them valuable additions to any coin collection for collectors interested in United States coins.