From 1827 until 1841, Dr. Ray engaged in private practice in Maine while developing a specialty in mental illness. In 1838 published a major work entitled a Treatise on the Medical Jurisprudence of Insanity that went through five editions by 1863. The book established Ray as an expert in this field and led to his appointment as medical superintendent at the Maine State Hospital where he presided from 1841 to 1845. While at his Maine post, Ray, along with twelve other medical superintendents of public and private hospitals for the insane, founded an organization in 1844 that evolved into the American Psychiatric Association.
During his tenure at Maine’s major mental facility, Dr. Ray accepted the directorship of Butler Hospital in Providence, then just in its planning stage. Ray had returned from a survey tour of European mental hospitals by December, 1847 when Butler Hospital admitted its first patient. For the next two decades, until his departure for Philadelphia in 1866, Ray operated the hospital in its tranquil pastoral setting on the west bank of the Seekonk River. A private facility originally endowed by gifts from Cyrus Butler, for whom the facility is named, and Nicholas Brown, the hospital was an early example of the “asylum” approach to the treatment of the mentally ill and a vast improvement over the prison-like facilities then prevalent for housing the insane.
During Ray’s period of superintendency, he continued to write and lecture on the professional care of the mentally ill, earning an international reputation for his insights on both the legal aspects of confinement for mental illness and the treatment of this disease.
Ray spent the last decade of his life in Philadelphia where his physician son Benjamin Lincoln Ray had gone to set up a general practice of medicine. He died in 1879. According to one historian of the psychiatric profession in America, “Isaac Ray was one of the outstanding intellects among the founders of the American Psychiatric Association, and by example, as well as by his prolific and articulate writings, did more than any other American psychiatrist of his time to advance the medical professionalization of the care of the mentally ill.”