1870-S Seated Liberty Dollar

In 1870, the San Francisco Mint struck a small number of silver dollars that were never recorded in any official production log. No mintage figure exists. No congressional authorization mentions them. For over 150 years, the 1870-S Seated Liberty Dollar has remained one of American numismatics' deepest mysteries. About 12 copies are known to exist, most of them worn from circulation, and even the most damaged specimens sell for six figures.

Quick Value Summary

• Item: 1870-S Seated Liberty Silver Dollar

• Year: 1870

• Mint: San Francisco (S mint mark)

• Denomination: $1

• Composition: 90% silver, 10% copper (0.77344 oz pure silver)

• Condition Range:

  • VG-8 to Fine: $240,000 - $400,000
  • VF-20 to EF-40: $400,000 - $650,000
  • AU-50 to AU-58: $700,000 - $1,200,000
  • MS (Uncirculated): $1,500,000 - $1,800,000+

• Record Sale: Approximately $1.8 million (the single known uncirculated example)

• Known Population: About 12 specimens

• Rarity: Extremely Rare

The Story

On May 25, 1870, the cornerstone of the second San Francisco Mint building was laid at the corner of Fifth and Mission Streets. By some accounts, a set of commemorative coins was placed inside that cornerstone, and one of them was an 1870-S silver dollar. Whether this legend is true remains debated, but it is one of the most popular theories for why the coins were struck.

The San Francisco Mint had no authorization to produce silver dollars in 1870. The Philadelphia Mint struck 415,000 regular 1870 silver dollars, and the Carson City Mint produced 11,758. But San Francisco? The records are silent. No mintage figure appears in Treasury Department reports. No production orders survive.

Some researchers believe that only 12 coins were ever made. Others argue that fewer than that were intended to survive. The coins may have been struck as presentation pieces for the cornerstone ceremony, distributed to local officials and mint employees. Whatever the purpose, the 1870-S dollar was never meant for commerce. The fact that most surviving specimens show circulation wear suggests that some recipients spent their coins, not realizing they held something extraordinary.

The first example to attract serious collector attention surfaced in the late 19th century. Over the following decades, additional specimens appeared one or two at a time. Each discovery made headlines in the numismatic community. The single finest known example, graded about uncirculated to mint state, sold for approximately $1.1 million in 2003. Adjusted for market trends, that coin would likely exceed $1.5 million today.

In a 2008 auction, a PCGS XF-40 example sold for $632,500 through Bowers and Merena. That sale set a benchmark for the grade and demonstrated that even well-worn examples command prices most collectors will never have the opportunity to spend.

How to Identify It

The 1870-S Seated Liberty Dollar shares the same basic design as other Seated Liberty dollars from 1840 to 1873, designed by Chief Engraver Christian Gobrecht.

Obverse: Lady Liberty seated on a rock, holding a liberty pole with a Phrygian cap in her left hand and a shield in her right. Thirteen stars surround the border, with the date 1870 at the bottom.

Reverse: An eagle with outstretched wings, holding arrows and an olive branch. The motto "IN GOD WE TRUST" appears on a banner above the eagle. "UNITED STATES OF AMERICA" and "ONE DOL." surround the design.

Mint mark: The "S" mint mark is located on the reverse, below the eagle and above the "ONE DOL." denomination. It is small but legible on genuine specimens.

Key measurements:

• Diameter: 38.1 mm

• Weight: 26.73 grams

• Edge: Reeded

What to watch for: Because the 1870-S is so valuable, altered coins are a real threat. The most common alteration involves adding an "S" mint mark to a genuine 1870 Philadelphia dollar (no mint mark). Philadelphia 1870 dollars are worth $395 to $2,500 depending on grade, making the incentive for alteration enormous.

Value by Condition

With only about 12 known specimens, every transaction is a major event.

Circulated grades (VG through EF): Most known examples fall in this range. An 1870-S dollar in VG-8 to Fine condition has sold for $240,000 or more. In EF-40, the PCGS example that sold in 2008 brought $632,500. The wear on these coins tells a story. Someone in 1870s San Francisco likely spent this coin at a general store without a second thought.

About Uncirculated (AU-50 to AU-58): A very small number of examples survive with only light wear. These are estimated in the $700,000 to $1.2 million range, though so few exist that each sale is unique.

Uncirculated: Only one example is known in uncirculated condition. It sold for approximately $1.1 million in 2003. At current market levels, numismatists estimate it could bring $1.5 to $1.8 million or more.

Values have trended consistently upward over the past 50 years. The 1870-S dollar benefits from being both extremely rare and extremely famous. It appears on virtually every "top 25 rarest U.S. coins" list, which drives demand from wealthy collectors who view it as a trophy piece.

Comparison to Other 1870 Seated Liberty Dollars

The contrast is staggering. A Philadelphia 1870 dollar in VG condition costs about $395. The same date with an "S" mint mark costs about $240,000. That single letter is worth a house.

Authentication and Fakes

The 1870-S dollar is one of the most commonly faked U.S. coins. The alteration method is straightforward: take a genuine 1870 Philadelphia dollar and add a fake "S" mint mark to the reverse.

How to spot fakes:

• Mint mark style: The genuine 1870-S uses a specific punch style that differs from the "S" used on other San Francisco coins of the era. Professional authenticators compare the shape, size, and positioning against known genuine examples.

• Die characteristics: The genuine 1870-S was struck from specific dies with unique characteristics (die cracks, polish lines, etc.) documented by PCGS and NGC. Any coin that does not match the known die state is suspect.

• Surface examination: Added mint marks often leave tooling marks visible under magnification. The field around the mint mark may show disturbance that is absent on genuine coins.

Never buy an 1870-S dollar without PCGS or NGC certification. At six-figure prices, the cost of professional authentication ($100 to $300 for a standard submission) is negligible. Both PCGS and NGC have authenticated multiple genuine examples and have detailed records of the known population.

Where to Sell

If you have a genuine 1870-S Seated Liberty Dollar, you own one of the rarest coins in American history.

Major auction houses: Heritage Auctions and Stack's Bowers are the leading venues for six- and seven-figure coin sales. They have the marketing reach and collector base to maximize your result. Expect buyer's premiums of 20% to 25% (paid by the buyer, not the seller), but sellers typically pay a consignment fee of 5% to 10%.

PCGS or NGC certification is mandatory before selling. Submission at the appropriate value tier costs $300 to $600+ for coins declared at $50,000+. Turnaround times vary.

Insurance and shipping: For a coin worth $500,000+, insured registered mail through USPS or an armored courier is standard. Expect $200 to $500+ in shipping and insurance costs.

Not sure about the condition of yours? Upload a photo to Curio Comp for an initial assessment.

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