The Mattachine Society founded in 1950, was one of the earliest LGBT organizations in the United States, probably second only to Chicago’s Society for Human Rights. Communist and labor activist Harry Hay formed the group with a collection of male friends in Los Angeles to protect and improve the rights of gay men. Branches formed in other cities and by 1961 the Society had splintered into regional groups.

This French group was named in turn after Mattaccino, a character in Italian theater. Mattaccino was a kind of court jester, who would speak the truth to the king when nobody else would. The “mattachin” (from Arabic mutawajjihin—”mask-wearers”) were originally Moorish (Hispano-Arab) sword-dancers who wore elaborate, colorful costumes and masks.

The Mattachine Society used so-called harlequin diamonds as their emblem. The design consisted of four diamonds arranged in a pattern to form a larger diamond.

During the 1960s, the various unaffiliated Mattachine Societies, especially the Mattachine Society in San Francisco and MSNY, were among the foremost gay rights groups in the United States, but beginning in the middle 1960s and, especially, following the Stonewall riots of 1969, they began increasingly to be seen as too traditional, and not willing enough to be confrontational. Like the divide that occurred within the Civil Rights Movement, the late 1960s and the 1970s brought a new generation of activists, many of whom felt that the gay rights movement needed to endorse a larger and more radical agenda to address other forms of oppression, the Vietnam War, and the sexual revolution. Several unaffiliated entities that went under the name Mattachine eventually lost support or fell prey to internal division.

In 2002, Mattachine Midwest was inducted into the Chicago Gay and Lesbian Hall of Fame. A new Mattachine Society of Washington, D.C. was formed in 2011 and is dedicated to original archival research of LGBT political history.