4th c. BC Hippocratic medical texts

2nd c. AD Galenic medical texts

1533 Henry VIII criminalizes “buggery,” making it punishable by death and the loss of property

1610 The Virginia Colony establishes sodomy as a capital crime; other American colonies follow suit

1710? Anonymous publication in England of Onania, or the Heinous Sin of Self-Pollution

1760 Onanism, or a Medical Dissertation on the Diseases Produced by Masturbation by Samuel-Auguste-André-David Tissot

1789-1799 French Revolution

1791 French Constituent Assembly (1789-1791) deletes antisodomy laws from the new French penal code. This subsequently becomes the model for the decriminalization of sodomy in other countries.

1809 Philosophie zoologique by Jean-Baptiste de Lamark

1857 Treatise on the Physical, Intellectual, and Moral Degeneration of the Human Species and the Causes of these Morbid Varieties by Bénédict A. Morel

1857 Medico-legal Study of Crimes Against Decency by Ambroise Tardieu

1859 On the Origin of Species by Means of Natural Selection by Charles Darwin

1861-1865 U. S. Civil War

1864-79 Pamphlets by Karl Heinrich Ulrichs defending same-sex love as a biological phenomenon

1866 General Morphology of Organisms Ernst Haeckel

1868 First German usage of homosexual and heterosexual, in a letter from Karl Maria Kertbeny to Karl Ulrichs

1869 A Practical Treatise on Nervous Exhaustion (Neurasthenia) by George Beard

1869 Karl Ernest Westphal describes “contrary sexual sensation” (conträre Sexualempfindung) as a neuropathic and psychopathic condition

1871 Passage of German Paragraph 175, a law that criminalized "unnatural fornication" between males

1878 Arrigo Tamassia renders Westphal’s term into Italian as inversione dell'istinto sessuale (inversion of the sexual instinct)

1886 Psychopathia Sexualis by Richard von Krafft-Ebing

1892 Alice Michel lesbian “lust murder” case

1895 Oscar Wilde trials

1897 Sexual Inversion by Havelock Ellis and John Addington Symonds

1897 Magnus Hirschfeld founds the Scientific Humanitarian Committee to defend the civil rights of homosexuals

1898 George Bedborough put on trial for selling Havelock Ellis's Sexual Inversion.

1901 The Social Problem of Sexual Inversion by Magnus Hirschfeld

1905 Three Essays on the Theory of Sexuality by Sigmund Freud

1910 Transvestites: The Erotic Drive to Cross-Dress by Magnus Hirschfeld

1914-1918 World War I

1920 “The Psychogenesis of a Case of Homosexuality in a Woman” by Sigmund Freud

1921 Edward Kempf’s Psychopathology describes “homosexual panic”

1924 Henry Gerber and six friends establish the Society for Human Rights, the first American homosexual rights organization

1929 Factors in the Sex Life of Twenty-two Hundred Women by Katharine Bement Davis

1932 “On Female Homosexuality” by Helene Deutsch

1933 Adolph Hitler and the National Socialist (Nazi) party come to power in Germany

1934 Embryology and Genetics by Thomas Hunt Morgan

1935 Sigmund Freud states in his "Letter to an American Mother" that, "Homosexuality is assuredly no advantage, but it is nothing to be ashamed of, no vice, no degradation; it cannot be classified as an illness."

1935 The Committee for the Study of Sex Variants is formed

1935 Egas Moniz develops “frontal lobotomy” or leucotomy in Portugal

1935 First use of electrical shock in aversive treatment of homosexuality

1937 J. Edgar Hoover declares “War on the Sex Criminal!”

1939-1945 World War II

1939 Sigmund Freud dies in London

1940 Sandor Rado’s “A Critical Examination of the Concept of Bisexuality”

1940 Newdigate Owensby promotes pharmacological shock therapy for the treatment of homosexuality

1940 Selective Service Medical Circular No. 1 recommends that doctors screen out homosexuals from military draftees

1941 Bombing of Pearl Harbor; United States enters World War II

1944 “Eight Prerequisites for the Psychoanalytic Treatment of Homosexuality” by Edmund Bergler

1948 Sexual Behavior in the Human Male by Alfred Kinsey, Wardell Pomeroy, and Clyde Martin

1949 D. O. Cauldwell first describes “psychopathic transsexualism”

1950 Beginning of Senator Joseph Macarthy’s hearings on communists in the government; purges of homosexuals from government

1951 The Homosexual in America by Edward Sagarin under the pseudonym Donald Webster Cory

1951 Mattachine Society founded in Los Angeles

1951 Patterns of Sexual Behavior by Clellan S. Ford and Frank A. Beach

1952 The first edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM) groups the "sexual deviations" (including homosexuality) under the category of “sociopathic personality disorders”

1952 Franz J. Kallmann’s “Twin Sibship Study of Overt Male Homosexuality”

1952 George Jorgensen undergoes sex reassignment surgery in Denmark to become Christine Jorgensen

1953 First volume of ONE Magazine: The Homosexual Viewpoint

1953 Sexual Behavior in the Human Female by Alfred C. Kinsey, Wardell B. Pomeroy, Clyde E. Martin and Paul H. Gebhard

1954 Female Homosexuality by Frank Caprio

1955 Daughters of Bilitis founded in San Francisco

1956 Evelyn Hooker begins publishing research on the psychology of non-clinical homosexuals, based on work begun in the 1940s

1957 British Wolfenden Commission recommends decriminalization of homosexuality

1960 Kurt Freund uses pharmacological aversion therapy to cure homosexuality

1961 The Myth of Mental Illness by Thomas Szasz

1961 Madness and Civilization by Michel Foucault

1962 Homosexuality: A Psychoanalytic Study by Irving Bieber

1964 M. P. Feldman and M. K. MacCulloch report on the use of electric shock aversion therapy in the treatment of homosexuality

1965 Sexual Inversion:   The Multiple Roots of Homosexuality by Judd Marmor

1965 Washington Mattachine Society adopts a resolution declaring that “homosexuality is not a sickness”

1968 The Overt Homosexual by Charles W. Socarides

1968 Homophile activists protest against Dr. Charles Socarides at the American Medical Association meeting in San Francisco

1968 DSM-II reclassifies the sexual deviations as a separate category of personality disorders

1969 The Stonewall Inn riots in New York’s Greenwich Village ignites a radical gay rights movement

1969 National Institute of Mental Health Task Force on Homosexuality, headed by Evelyn Hooker, completes its Final Report; publication delayed until 1972

1970 Gay rights activists storm panels on homosexuality at the American Psychiatric Association (APA) annual convention in San Francisco

1970 First Christopher Street Liberation Day March in New York City commemorating the Stonewall riots

1971 Annual APA meeting in Washington DC features first-ever panel of gay people speaking about " Lifestyles of Non-Patient Homosexuals"

1972 APA annual meeting sponsors panel--"Psychiatry:   Friend or Foe to Homosexuals:   A Dialogue"--that includes gay activists, gay sympathetic psychiatrists, and a disguised gay psychiatrist, Dr. H Anonymous (John Fryer, MD)

1972 John Money and Anke A. Ehrhardt’s Man & Woman, Boy & Girl: Differentiation and Dimorphism of Gender Identity from Conception to Maturity reports on research started in the 1950s

1972 Lesbian/Woman by Del Martin and Phyllis Lyon

1973 Board of Trustees (BOT) of the APA approves the deletion of homosexuality from the DSM-II and substitutes a diagnosis of “Sexual Orientation Disturbance”

1974 Referendum organized by antigay psychoanalysts to overturn APA BOT decision is defeated.   APA members support BOT decision to remove homosexuality by significant majority

1977 The Joy of Gay Sex by Charles Silverstein and Edmund White

1978 Homosexualities: A Study of Diversity Among Men and Women by Alan P. Bell and Martin S. Weinberg

1980 Outbreak of genital herpes in the U. S.

1980 DSM-III creates a new class, the “psychosexual disorders,” including psychosexual dysfunction, paraphilia (fetishism), gender identity disorder (transsexualism), and “ego-dystonic homosexuality”

1981 Sexual Preference:   Its Development in Men and Women by Alan P. Bell, Martin S. Weinberg and Sue K. Hammersmith

1981 Homosexuality and American Psychiatry:   The Politics of Diagnosis by Ronald Bayer

1981 First reports of a new immunodeficiency syndrome in homosexual men

1982 APA establishes the a Caucus of Homosexual-Identified Psychiatrists which later becomes the Caucus of Lesbian, Gay and Bisexual Psychiatrists

1985 Establishment of the Association of Gay and Lesbian Psychiatrists

1982 U.S. Centers for Disease Control adopt the name Acquired Immune Deficiency Syndrome (AIDS)

1982 French virologist Luc Montagnier isolates LAV (lymphadenopathy-associated virus) as the causative agent of AIDS

1982 American virologist Robert Gallo isolates HTLV-III (human T-cell lymphotropic virus type III) as the causative agent of AIDS

1986 The name Human Immune Deficiency Virus (HIV) adopted by consensus

1987 AIDS Coalition to Unleash Power (ACT-UP) forms in New York City

1987 President Ronald Reagan speaks publicly about AIDS for the first time

1987 DSM-III-Revised deletes the diagnosis of homosexuality entirely, leaving the paraphilias and sexual dysfunctions as the two main classes of "sexual disorders"

1989 First issue of Journal of Gay and Lesbian Psychotherapy, the official journal of the Association of Gay and Lesbian Psychiatrists

1990 APA issues position statement opposing discrimination against gay people in the military

1990 Dutch neuroscientists, Dick Swaab and Michel Hofman, first report on neuroanatomical differences between homosexual men and a reference group

1991 J. Michael Bailey and Richard C. Pillard publish findings on high concordance rate of homosexuality in twins

1991 Simon LeVay reports on a difference in hypothalamic structure between heterosexual and homosexual men

1991 Sandy Stone’s “Posttranssexual Manifesto”

1991 American Psychoanalytic Association issues position statement opposing discrimination on the basis of sexual orientation in the selection of psychoanalytic candidates

1992 American Psychoanalytic Association modifies position statement opposing discrimination on the basis of sexual orientation to include faculty, supervising and training analysts

1993 Dean Hamer and colleagues report on a linkage between DNA markers on the X chromosome and homosexuality

1993 President Bill Clinton's unsuccessful effort to end discrimination against gays in the military leads to the compromise:   Don't Ask, Don't Tell

1993 Cheryl Chase founds the Intersex Society of North America (ISNA)

1994 DSM-IV groups sexual dysfunction, the paraphilias, and gender identity disorder under the heading “sexual and gender identity disorders”

1995 Release of Saquinavir, the first protease inhibitor, for the treatment of HIV disease

1996 US Supreme Court strikes down as unconstitutional Colorado's antigay Amendment Two which nullified then-existing civil rights protections for gays and also barred the passage of new anti-discrimination laws

1996 US congress passes Defense of Marriage Act (DOMA), a law signed by President Clinton, and prohibits the federal government from recognizing same-sex marriages

1997 American Psychoanalytic Association becomes first mainstream mental health organization to support marriage equality (same-sex marriage)

1998 APA officially criticizes efforts to change sexual orientation

2000 Vermont becomes first US state to offer gay people civil unions

2000 APA issues two position statements, one in support of same sex civil unions and the other asking ethical psychiatrists to refrain from practicing conversion or "reparative therapies"

2001 The Netherlands becomes the first country to legalize marriage equality

2002 American Academy of Pediatrics issues position statement in support of second parent adoptions for same-sex couples; APA follows suit with a similar position statement that same year

2003 US Supreme Court strikes down as unconstitutional state sodomy laws in the 13 states that still criminalized consensual, adult homosexual behavior

2003 Belgium legalizes marriage equality

2004 Gay marriage legalized in the US state of Massachusetts

2004 American Psychological Association issues positions statement in support of marriage equality

2005 APA issues a position statement in support of same sex civil marriage

2005 Canada and Spain legalize marriage equality

2006 South Africa legalizes marriage equality; Israel, which does not permit civil marriages, recognizes gay marriages performed in other countries