Not nearly as much is known about the editor of the American Edition of Boydell's Shakespeare Gallery. The introductory material to the text only includes his reasons for pursuing the project, and his other work, A Biographical History of the Fine Arts, also contains a dearth of personal information.
Spooner's birth and death date come to us from his Wikipedia page, and the source listed is no longer in tact.He was born in 1809, and passed away in 1859, just seven years after he completed his ambitious project. It is worth noting that the Wikipedia page does not even include this wonderful collection of engravings in his list of works.
In the introductory materials, Spooner tells us that he undertook this project in a similar situation to Boydell: it was a project deemed too expensive and large for a single individual, and yet he chose to do it anyway. He is very free in telling us that this project set him back roughly $50,000, an immense sum in 1850.
The project required hiring a new team of engravers to restore the original plates to a usable condition, as time and wear had rendered them all but useless for further printing. He was able to bring all of the plates back to usable condition, and subsequently published the photos by sending his subscribers two at a time over the course of roughly four years, with the idea that they would each then place them in their own bound collection.
Though the actual Gallery is only available in its entirety in rare books libraries, Spooner's "Prospectus for publishing an American Edition of Boydell's Illustrations of Shakespeare" has been scanned, and is available online.
All biographical information, unless otherwise noted, comes from The American Edition of Boydell's Illustrations of the Dramatic Works of Shakspeare, by the most Eminent Artists of Great Britain. Vols. 1 and 2. New York: Restored and Published with Original Descriptions of the Plates by Shearjashub Spooner, A.B M.D., 1852. Courtesy of the Trustees of the Boston Public Library/Rare Books; or the "Prospectus for publishing an American Edition of Boydell's Illustrations of Shakespeare." New York: J. J. Reed, Printer. 1849.
The Second Volume of The American Shakespeare Gallery
in the Rare Books Room at the Boston Public Library. The
pages are roughly 24 inches by 30 inches, according to
Boydell's prospectus.