Few events have tested the APS more than the American Revolution, a period that witnessed the departure of Loyalists and Quaker pacifists from its halls, the suspension of its meetings, and the dispersal of collections. Lying moribund for nearly a decade, the Society was revived only when its founder, Benjamin Franklin returned from his ministry in France, and dedicated himself to its revival. Within a year, the energetic patriarch of the Society had turned it around. In 1786, construction began on a new building, Philosophical Hall, which was intended as a permanent home for the Society, and once again the APS became the site for the vigorous discussion of scientific and cultural affairs.

Yet as much as the APS was tested in the century's greatest political conflict, the members who remained played a uniquely important role in helping to shape the course of events. From Franklin and Jefferson, to Adams, Washington, and Lafayette, many of the luminaries in the Revolutionary cause became deeply attached to the Society, and as a result, the collections of the APS took on a distinctly revolutionary cast. Nowhere is this history better reflected than in three of its best known items, remarkable copies of that seminal revolutionary document, the Declaration of Independence.

Many of the most dramatic scenes of the independence movement were played out within two blocks of the current home of the APS, from the drafting of the Declaration, to its ratification and distribution. Four of the five members of the drafting committee would become members of the Society, including the two most important, Jefferson and Franklin (Roger Sherman was the exception), and perhaps more impressively, fifteen members signed the Declaration. In more obscure ways, too, the APS contributed to the revolutionary platform -- in one case, physically. When the Declaration was read publicly in the State House yard on July 8th, 1776, John Nixon stood on a platform that had been erected by the APS for David Rittenhouse to observe the transit of Venus in 1769. As it was read, the crowd cheered and the King's arms were torn down from the State House. That evening, all across the city, bonfires blazed amid the pealing bells and "other great Demonstrations of Joy."

As talk of a formal break with Britain began to grow among the members of the Continental Congress, a delegate from Virginia, Richard Henry Lee, became the first to propose issuing a declaration of independence. Days later, on June 11th, as a drafting committee was being appointed, Lee was unexpectedly called home to tend to his ailing wife. During his absence, his old friend, Thomas Jefferson, drew up an aggressively eloquent document, producing fair (exact) copies in his own hand as a record. Jefferson submitted his draft to Congress on July 1st, and to keep his old friend Lee apprised of events, Jefferson forwarded a copy seven days later. Lee's brother, Arthur, later a great diplomat, wrote in the margins to record the changes in wording that so annoyed Jefferson: from small changes of phrasing to striking a passage condemning slavery to appease the delegates from South Carolina and Georgia and (as Jefferson observed) to ease the consciences of those northern delegates who traded in slaves.

Having been thoroughly vetted among the members of Congress during the debates of July 2nd and 3rd, the Declaration of Independence was formally approved during the momentous session of July 4th. That afternoon, a copy was rushed to the print shop of John Dunlap on Market Street, and that night, the type was set for the first printing. It was quick work, indeed. By the morning, a stack of copies was delivered to the waiting delegates in the State House, and others were prepared to be sent for public reading to each of the state assemblies and to the various committees of safety, as well as to the commanding officers of the Continental troops. It was a copy similar to this one that John Nixon read aloud in the State House yard on the 8th.

Although the original number printed is unknown, fewer than 25 copies survive. This fairly healthy number probably reflects the great importance that was almost immediately attached to the document, as well as its official nature. The APS copy of Dunlap's first edition of the Declaration was acquired in 1901 in an exchange of duplicate materials with the Library of Congress. In return, the Library of Congress received a copy of Franklin's famous hoax, Supplement to the Boston Independent Chronicle, no. 705, of March 12, 1782.

Although the first printing of the Declaration is among the best known of all American imprints, the vellum printing is much rarer. At some time before July 19th, John Dunlap returned to his shop to reset the type for a second printing. This issue, somewhat larger in size than the first, was printed in a very small number on a more durable substrate, vellum. We can only speculate on why Dunlap went through the trouble to prepare a second edition so soon, and why he might have chosen to print on vellum. Currently, the best guess is that he, too, recognized the significance of the political act of claiming independence, and sought to create an edition that captured the momentous importance of that act in a more permanent fashion.

A close friend of the printer, David Rittenhouse, seems to have acquired the vellum Declaration at about the time of printing. An instrument maker and astronomer, as well as the second President of the APS, Rittenhouse was an ardent patriot and an active member of the Committee of Safety during the Revolution. Clearly, Rittenhouse had both the motive and opportunity to acquire a copy of the Declaration. It descended from Rittenhouse's family to the physician, James Mease, who donated it to the Society in 1828. It is the only copy known of this printing.