Dr. St. John pursued a preparatory course of study in the Albany schools and then began to fit himself for the profession of medicine, entering the office of Dr. H. W. Bell, of Berne, N.Y., and afterward the office of Professor James II. Armsby, then the leading surgeon of Albany. He took a course of lectures at the Albany Medical College, the Buffalo Medical College, and the Bellevue Hospital Medical College, graduating from the latter institution with the degree of M.D. in 1875.

Upon graduation Dr. St. John settled in Hackensack, N. J., where he has since resided, and where he has acquired one of the largest and most successful practices in Eastern New Jersey. He is not only prominent in the profession of medicine and surgery, but has also been closely identified with all matters of local or public interest. He was the first to realize the need and advantages of a hospital for the better treatment of a class of medical and surgical cases, and in 1888 was instrumental in organizing the Hackensack Hospital, one of the most useful institutions in Bergen County. While his energetic and untiring efforts in its behalf have been ably seconded by all classes of citizens, his indefatigable labors have been the primary cause of its success, and under his able direction as President of the Medical Board and visiting physician and surgeon the hospital has outgrown its present quarters and is being replaced by a much larger structure, which will be one of the best equipped institutions of its class in the State. One wing of the new building, consisting of two wards, will be known as the St. John wards, Dr. St. John having assumed the cost of this part. Another wing will be the Frank B. Poor wards, that gentleman having given the amount necessary for its construction. Dr. St. John is a member and former President of the Bergen County Medical Society, and a member of the New Jersey State Medical Society, the New York State Medical Association, the New York Academy of Medicine, and the American -Medical Association. He was appointed by Governor Griggs one of the managers of the New Jersey State Hospital for the Insane at Morris Plains, and is surgeon for the Erie Railroad. He also does a great deal of surgical work in the western portion of Bergen County outside of his hospital practice. Associated with him is Dr. A. A. Swayze, a graduate of the College of Physicians and Surgeons of Baltimore, Md.

Dr. St. John is First Vice-President of the Hackensack Trust Company, a Director of the Hackensack Bank and of the Gas and Electric Company of Bergen County, and President of the Hackensack Heights Association, owners of a large tract of valuable real estate on Hackensack Heights.