1855 Half Dollar. Unique. Trial piece struck from regular dies. Possibly the first piece struck by the U.S. Mint in aluminum. Currently in the Princeton University collection (Numismatic Collection, Department of Rare Books and Special Collections, Princeton University Library).
| Country | United States of America |
| Year | 1855 |
| Serie | Patterns |
| Denomination | P50c |
| Mint | Philadelphia |