The 1878 provides a massive jump in mintage for the Proof Three Cent Nickel Series with 2,350 pieces struck. Common up to PR66, which is scarce. Anything finer would be considered rare. Collectors should not fear as examples with stunning color and strong strike can be located with some effort. Cameos bring a small, gradual premium with an increase in rarity and demand coming from the deep cameos.
| coinage-type | Three cent nickel |
| desg | PR |
| designer | James B. Longacre |
| diameter | 17.9 |
| edge | Plain |
| material | 75% copper; 25% nickel |
| mintage | 2,350 |
| ngc-id | 275Y |
| obverse-description | A Romanesque Liberty is portrayed facing left with LIBERTY emblazoned on her crown. UNITED STATES OF AMERICA appears on the periphery with the date at the bottom. |
| pcgs-link | 3774 |
| pcgs-number | 3774 |
| prefix | Proof Only |
| reverse-description | The roman numeral III is centered in the design surrounded by a large wreath tied with a bow at the bottom. This design is one of few American coins without wording on one of the sides. |
| weight-grams | 1.94 |
| year-display | 1865-1889 |