Dr. McFarland was born in Concord, New Hampshire, and educated at Dartmouth and Jefferson Medical College. Appointed Superintendent of the New Hampshire Asylum for the Insane (1845–54) and the Central Hospital for the Insane at Jacksonville, Ill., (1854–70), he served as an advocate for the cottage system of hospital care for the insane and established the private asylum Oak Lawn Retreat in Illinois.
Dr. McFarland served as President of the Association of Medical Superintendents of American Institutions for the Insane (1859–62).