In 1847 he graduated at the College of Physicians and Surgeons (old Crosby Street school), and in the following year establishedhimself in Yonkers as an allopathic physician. Shortly afterward he was induced to investigate honKL'opathy, the result being a conviction as he said of its superiority over the old system of practice. He at once became its strong advocate and the pioneer practitioner in the county. His success in introducing the new system was most marked ; he grew rapidly in favor with the community, acquiring wealth and a pre-eminent position among the physicians of the locality.

Notwithstanding his change of faith, the relations between himself and his old teacher. Professor Parker, greatly to the honor of the latter ever continued of the most friendly character.

Dr. Flagg avoided politics entirely, and never held any public office of a political character. He always devoted himself wholly to his profession, in which he was a zealous and untiring worker ; a portion of a year spent in Europe and a short time in Mexico, being almost the only relaxation he allowed himself between the commencement of his practice and his death on May 15, 1884.

When, in 1865, the Westchester County Homoeopathic Medical Society was organized, he was elected its president and held that office for three years. He was also a member of the American Institute of Homoeopathy.

He married on May 17, 1848, Charlotte Whitman, of Hartford, Conn., and had eight children, five of whom are still living. Their names are Howard W., Marietta W., Lucy W., George A. and Robert N. Flagg, M. D., who succeeds to the practice of his father.'