| 1878 | Martin Buber was born. Buber was a Jewish existentialist philosopher whose description of the intimate "I-Thou relationship" with God influenced humanistic theories of personality and psychotherapy. |
| 1879 | The state of Colorado enacted legislation establishing the state's first public mental hospital, the Colorado Insane Asylum, now named Colorado Mental Health Institute Pueblo. The first patients were admitted in October, 1879, to a temporary hospital located in an existing building near Pueblo, Colorado. The permanent hospital building opened on November 20, 1883. P. R. Thombs was medical superintendent of the hospital for its first 20 years. |
| 1892 | Selig Hecht was born. Hecht discovered the processes of decomposition and regeneration of photopigments in the retina that transduce light energy into neural impulses. His work serves as a foundation of modern vision theory. |
| 1897 | Rudolf Dreikurs was born. Dreikurs was a major interpreter of Adlerian personality theory, concentrating on the behavior of children and a functional analysis of misbehavior. |
| 1904 | Edward F. Buchner of the University of Alabama wrote to prominent philosophers and psychologists regarding interest in a regional psychological association in the southeastern United States. The result was the organizing meeting of the Southern Society for Philosophy and Psychology, held in Atlanta, Georgia, on February 23, 1904. |
| 1911 | Freudians attacked the theories of Alfred Adler and his followers at a meeting of the Vienna Psychoanalytic Society. Adler resigned the presidency of the organization shortly afterward and founded his own Society for Individual Psychology in 1912. |
| 1954 | The Tennessee Psychological Association was legally incorporated. |
| 1973 | After a presentation by Charles Silverstein, the Nomenclature Committee of the American Psychiatric Association agreed to review the status of homosexuality as a psychiatric disorder. This was an important step in the eventual deletion of homosexuality as a pathological condition in the Diagnostic and Statistical Manual of Mental Disorders. |
| 1988 | The National Institute of Mental Health Advisory Council adopted a major new research program directed at causes and treatment of schizophrenia. |
| 1991 | The APA Council of Representatives voted to admit Division 49 (Group Psychology and Group Psychotherapy). Arthur Teicher headed the petitioning group and was the division's first president pro tem. |
| 1991 | The organizing meeting of the APA Rural Health Caucus was held in Washington, DC. The Rural Health Caucus promotes improvement of psychological research, teaching, and clinical practice in rural communities. |