At the beginning of the American Revolutionary War, he went to Edinburgh, where he was known as an able scholar, and took the degree of M.D., presenting a thesis entitled “De Generatione Puris,” which was at one time famous.
He subsequently studied in Paris, London, and Leyden, and on his return settled in Philadelphia, and then in New York City, where he practised his profession.
He embarked in the William Blount conspiracy in instigating the Cherokee and Creek Indians to aid the British in their attempt to conquer the Spanish territory in Louisiana in 1797.
[1][2] His students included Valentine Seaman, who mapped the 1795 yellow fever epidemic in New York and introduced the smallpox vaccine to the United States in 1799.
[3] Dr. John W. Francis said of him: “He was unwearied in toil and of mighty energy, dexterous in legislative bodies, and at one period of his career was vested with almost all the honors the medical profession can bestow.” Romayne published an address before the students of the New York College of Physicians and Surgeons on The Ethnology of the Red Man in America (New York, 1808).