I have recently retrieved from my files the text of an address given by the late Dr. Francis R. Packard of Philadelphia before the College of Physicians of Philadelphia in 1900, and reprinted from The Philadelphia Medical Journal, March 10, 1900. It deals in the main with certificates of proficiency which, in the days before there were any medical colleges to grant diplomas, were provided to practitioners of medicine in the colonies to indicate their fitness for their calling.
It has been estimated that at the outset of the War of Independence there were in the country more than 3,500 persons practicing medicine and calling themselves physicians, of whom about 400 had received the degree of MD, or even BM. More recent studies would seem to show that this is too high an estimate, because, for one thing, it would indicate a greater number of qualified medical men according to
By These Presents.... Arch Intern Med. 1964;114(3):462-465. doi:10.1001/archinte.1964.03860090196026