The initial transcriptions were done by Donovan Rees, a specialist at London rare book and manuscript dealers Bernard Quaritch Ltd., who brought the documents to light after they were identified among the papers of a branch of the Barclay family.
The discovery was chronicled in the New York Times.
nytimes.com
The Founding Father Who Sought a Last-Minute Deal to Avert the Revolution
Recently discovered documents reveal a back-channel attempt by a leader of the Continental Congress to make peace. (He did not succeed.)