The 1877 Twenty Cent Piece is a proof-only issue in this extremely short series that is highly desired by collectors. It is the rarest of the 4 proof 20 Cents as a mintage of just 350. The date is scarce from the circulated grades all the way through PR66. The value escalates at a gradual pace up until the finest known grade of PR67, which is rare. The auction record for this date is a PCGS graded PR66, which brought $39,950 at a Legend auction in 2017. As cameo and deep cameo pieces go there is an expected, yet subtle, premium. Only 156 have a Cameo designation from PCGS and NGC and only 7 exist in Deep Cameo. Deep Cameos are very rare across all Twenty Cent dates.
| Country | United States of America |
| Year | 1877 |
| Serie | 20-Cent Pieces |
| Denomination | 20c |
| Mint | Philadelphia |
| coinage-type | Seated Liberty twenty cent piece |
| desg | PR |
| designer | William Barber |
| diameter | 22 |
| edge | Plain |
| fineness | 0.9 |
| material | 90% silver; 10% copper |
| mintage | 510 |
| ngc-id | 27H4 |
| obverse-description | Lady Liberty is seated on a rock, holding a staff, and bearing a shield with the word LIBERTY on a flowing ribbon. 13 stars have adorn the periphery and the date appears at the bottom center. |
| pcgs-link | 5305 |
| pcgs-number | 5305 |
| prefix | Proof Only |
| reverse-description | An eagle is prominently featured with the words UNITED STATES OF AMERICA * TWENTY CENTS around the periphery. |
| weight-grams | 5 |
| year-display | 1875-1878 |