The Pittman Act required the Mint to strike one replacement dollar for every coin melted in 1918, and that quota was a fixed number. In 1928 the arithmetic ran out. Philadelphia struck 360,649 dollars, the smallest circulation mintage of the Peace series, and then the presses simply stopped. The key date of the series exists because a law said exactly how many coins to make, and the Mint made them.
Collectors knew immediately. The 1928 was recognized as the low-mintage date from the day of release, and enough were set aside that the coin is obtainable in mint state today, though never cheap in any grade. This is scarcity of the most honest kind: not melted, not lost, just never numerous.
Its danger is its common sibling. San Francisco struck 1,632,000 dollars the same year, and the classic 1928 fraud is a 1928-S with the mintmark removed. The empty space on the reverse below ONE is where every raw 1928 should be inspected first.
The most transparent key date in American silver: everyone always knew there were only 360,649, and the price has reflected it for a century. Buy certified, check that mintmark area, and remember that a bargain 1928 is a 1928-S in costume until a grading service says otherwise.
| Issue | Mint | Mintage |
|---|---|---|
| 1928 Peace Dollar | Philadelphia | 360,649 |
| 1928-S Peace Dollar | San Francisco | 1,632,000 |
Mintage figures: United States Mint, Annual Report of the Director of the Mint, cross-checked across independent published references. Specifications: United States Mint coin specifications.