The 1866-S No Motto double eagle is a transitional issue in the Liberty series as 1866 saw the introduction of the Type 2 design. This date and mint is always seen with appreciable softness of strike to the high points on both sides. Additionally, virtually all survivors are heavily abraded, often with numerous deep, detracting marks. The S mintmark is often lightly impressed and, due to a combination of wear and abrasions, can be difficult to discern. The vast majority of survivors retain little, if any luster. The San Francisco Mint struck 120,000 double eagles in February 1866 using at least two Type 1 reverse dies before the facility received instructions from Philadelphia to commence production of the new Type 2 design. The 1866-S No Motto is the second rarest San Francisco Mint Type 1 Liberty Head double eagle after the 1861-S Paquet Reverse. Only 200 or so examples have survived in all grades, with VF being the norm. EF survivors are very scarce, while in AU the 1866-S No Motto is rare. In Mint State this issue is so rare as to be virtually unobtainable.

The unexpected Union defeat at Manassas, Virginia in 1861 struck deep at the morale of the nation. Reverend M.R. Watkinson of Ridleyville, Pennsylvania sent a petition to Secretary of the Treasury Salmon P. Chase requesting that that an inscription be placed acknowledging "Almighty God in some form in our coins." Chase approved of the request and instructed the Director of the Mint to create designs and prepare patterns with various versions of wording for proposal to Congress. The various proposals for the motto were reviewed and Congress passed the Act of April 22, 1864 which specified the addition of IN GOD WE TRUST on the newly created two-cent coin. It was not until the Act of March 3, 1865 was passed that the motto was to be added to all gold coins above the three-dollar denomination beginning in 1866 in addition to silver coins above the dime. Towards the end of 1865, the Philadelphia Mint prepared 1866-dated dies and shipped them to San Francisco in anticipation of the start of production. However, the new reverse dies were not yet ready, the San Francisco Mint proceeded with production of 1866 half dollars, half eagles, eagles, and double eagles using the older No Motto reverse dies then on hand. Meanwhile, the Philadelphia Mint refrained from production until the dies bearing the motto were available. It was not until at least March of 1866 that the new reverse dies arrived at the San Francisco facility and the older dies withdrawn.

It is estimated that 120,000 double eagles were struck with the No Motto reverse design using two dies, though mintage records of the time do not differentiate between the two varieties. As with much of the output from the San Francisco Mint of the era, the 1866-S No Motto double eagles entered commerce promptly and remained there for years of heavy use. Today some 200 or so surviving examples are known, the vast majority of which in VF or EF condition. Above that, the issue is a formidable condition rarity and for all intents and purposes unavailable in grades higher than AU. A strictly graded full Mint State specimen is a noteworthy event and will be the focus of much attention from double eagle connoisseurs.

The example to the left was sold by Stack's Bowers Galleries in August 2014 Auction, where it realized $188,000.