We searched the PA. Archives and the Archives in Washington DC. There is no documentation for the time period that indicates that John Bryson served. Also, the Veterans Administration does not have any documentation of his service.
His acceptance into the DAR is based on information from the book HEITMAN, HIST REG OF OFFICERS OF THE CONT ARMY DURING THE WAR OF THE REV, 1775-1783, P 129 published in 1914. The VA says the information contained in that book is just hearsay.
We should probably have more proof before we consider his military service. John Bryson is my fifth great grandfather