News | Jan. 20, 2022

Shaping the revolutionary endgame: George Washington letter arrives at DIA Museum

By Anita Bravo, DIA Public Affairs

On Jan. 14, the DIA Museum received the second of 18 letters from the George Washington Papers on loan from the Library of Congress.  

Dated July 18, 1780, the letter to General Washington is from John Mersereau, an operative in the Mersereau Spy Ring, and provides details on the forces of Gen. Henry Clinton, commander of the British army in North America, which were advancing to New York after capturing Charleston, South Carolina, in May 1780. 

In the letter, Mersereau provides Washington with information on Clinton’s senior leaders, troop numbers, the armaments and positions. Of note, the letter mentions ships under the command of British Adm. Thomas Graves that were outfitted with copper-sheathed hulls. This was cutting-edge technology that the Royal Navy had recently deployed to maximize time at sea between repairs and gain critical advantage at sea. 

The intelligence in Mersereau’s letter shaped Washington’s strategy in the final stretch of the Revolutionary War. Unable to discern Washington’s plans for New York, Clinton ordered Gen. Charles Cornwallis to fortify the British position in Virginia in March 1781 by building a port at Yorktown on the Chesapeake Bay. In response, Washington’s forces trapped and laid siege to Cornwallis’ forces. 

In September 1781, French naval forces defeated Graves, preventing him from aiding the British forces at Yorktown. His copper-hulled ships were forced to sail back to New York for repairs. Graves’ fleet finally departed for its return to Yorktown on Oct. 19, 1781 — the very day that Cornwallis surrendered to Washington. 

Or, as DIA historian Paul Isakson puts it, “Checkmate!” 

Isakson presided over the letter’s transfer to the DIA Heritage Gallery, which traces the history of DIA’s mission back to Washington’s successful intelligence operations during the American Revolution. The letter will be on display for three months, then traded for the next in the series.  

The George Washington Papers consist of nearly 77,000 documents kept by Washington between 1745 and 1799, including correspondence, diaries, and financial and military records. Held by the Library of Congress, it is the largest collection of Washington papers in the world. 

This particular letter is an excellent example of how Gen. George Washington gained key information on British naval assets and manning strength from spy networks across the colonies to defeat our first national enemy,” said Isakson. “Defense intelligence has played an important role in the United States since the birth of our great Nation.” 

As a description of British military power during the Revolutionary War, the letter connects DIA’s mission — to provide intelligence on foreign militaries to prevent and decisively win wars — to a national legacy of defense intelligence that spans three centuries.