Lawrence Hartmann is a child psychiatrist, social activist, and former President of the American Psychiatric Association (APA). Hartmann played a central role in the APA's 1973 decision to remove homosexuality as a diagnosis of mental illness from its Diagnostic and Statistical Manual. This change opened the modern era of LGBTQ rights by providing support for the overturning of laws against homosexuals and by advancing gay civil rights, including the right to marry.