Proof 1877 Half Dollars have the smallest mintage of any Proof Seated Liberty Half Dollar since the end of the Civil War (this came on the heels of the largest Proof mintage in the previous year). The smaller mintage is reflected in the PCGS Population Report, where the number of certified Proof 1877 Half Dollars is the lowest of the same period. This disparity makes the 1877 a "sleeper" in the series and a great value for collectors. Many Proof 1877 Half Dollar suffer from handling marks, hairlines, and overall improper storage, making it very difficult to find nice examples. Approximately 20% of the known survivors are Cameo Proofs. As with many of it's contemporaries, the 1877 Half Dollar is extremely rare as a Deep Cameo.