Frank Kameny, the gay-rights activist who coined the slogan “Gay Is Good,” died Tuesday at the age of 86. Kameny was a Harvard PhD who was discharged from the Army Map Service in 1957 for being gay. He sued and took his case to the Supreme Court—the first civil-rights claim based on sexual orientation that the Court ever considered. After losing, he co-founded the gay-rights group the Mattachine Society of Washington. In 1965, he led the first gay-rights demonstrations at the White House and Pentagon, and three years later he began rallying gay men and women with the motto, “Gay Is Good.” He died from a heart attack or heart failure.