2018 United States Mint Proof Set - 10 Pieces!. While each of the ten coins in this U.S. Proof Set is beautiful in its own right, the five one-year only America the Beautiful quarters are certainly the highlights. These coins constitute the ninth year of the series. The Midwest features prominently, with Michigan, Minnesota, and Wisconsin all represented, while coins from state parks in Georgia and Rhode Island rounding out the five. If you are looking for a way to appreciate the stunning, often overlooked designs of America’s circulated coinage, don’t miss your chance to own this 2018 U.S. Proof Set.