The proof Morgan Dollar series began in 1878 before the first business strikes flowed from the presses. From that time through 1904, the Philadelphia Mint struck proof Silver Dollars of this type every year for sale to collectors. Most issues in this specimen series are of roughly comparable rarity, but the 1878 7 Tailfeathers, 3rd Reverse has a deciced edge over the other P-mint proofs of this type. Additionally, the 1895 commands a strong premium in today's market, but not because it is appreciably rarer than any other issue of its era. Rather, the lack of a business strike 1895 Morgan Dollar means that extant proofs of this date are under extreme collector pressure.
The Philadelphia Mint did not produce a traditional proof Morgan Dollar delivery in 1921, but it did strike 12 proofs at the request of the highly influential Henry Chapman. These Chapman pieces are the only true proof Morgan Dollars to bear the 1921 date, although somewhere between 20 and 200 specimen-quality coins were also struck at the Philadelphia Mint to appease Farran Zerbe. Zerbe was the most influential ANA member of his day, and he had these coins produced to cool his anger over the Mint's failure to place the new Peace Dollar into circulation before the calendar advanced to 1922.
While the vast majority of proof Morgan Dollars were struck at the Philadelphia Mint, limited quanties of proofs were produced in the branch mints on special occasions and/or for presentation to distinguished persons. All branch mint proof Morgan Dollars are rare coins, and they would serve as centerpieces in the finest collection or investment portfolio.