Newly found treasure trove of Ben Franklin's Letters.

• Position: American History

A trove of Benjamin Franklin letters has turned up in the British Library. Discovered by Alan Houston, professor of political science at the University of California, Davis, they are copies of correspondence that have not been seen in more than 250 years. All dating from the spring and summer of 1755, the 47 letters by, to, and about Franklin are in the hand of one Thomas Birch, a contemporary of Franklin's who was a prodigious--almost inveterate--compiler and transcriber of historical documents.

The letters concern Franklin's involvement in the first phase of the French and Indian War, specifically Gen. Edward Braddock and what Franklin later called the "Wagon affair." The French and Indian War is the North American chapter of The Seven Years' War. The most important colonial clash between Great Britain and France, it resulted, by 1763, in the French loss of most of its colonial possessions in the New World. Yet, in 1755, that eventual outcome was not at all clear.

Following George Washington's defeat at Ft. Necessity the previous year, imperial authorities dispatched one of their top commanders, Gen. Braddock, to regain control of the frontier. Braddock landed in Virginia, tasked with capturing France's Ft. Duquesne in what today is Pittsburgh.

He had been promised 2,500 horses and 250 wagons by Virginia and Maryland for his 250-mile overland march. Instead, he received only 200 horses and 20 wagons, and exploded in anger. Franklin arrived just in time, offering to arrange the help of Pennsylvania farmers. Franklin was successful; Braddock, less so, as the general died in a surprise attack just a few miles short of the fort. About 1,000 of his 1,500 men in the field were killed or wounded.

Houston was working on his latest book, Benjamin Franklin and the Politics of Improvement, when he discovered the "new" letters. It was Houston's final day of his scheduled trip to England. The last document he asked to see in the Manuscripts Reading Room was catalogued as "Copies of Letters relating to the March of General Braddock" by Thomas Birch. Birch was a colorful figure and an important man in his own right--a member of the Society of Antiquaries of London and secretary of the Royal Society from 1752-65--but he "doesn't show up in any of the biographies on Franklin," Houston relates.

Houston was not looking for traces of Franklin in Birch's handiwork--which numbers an astonishing 400-plus volumes in the British Library. Rather, he was combing...