By the early 1970s a global gay rights movement championed the human rights of lesbian, gay, and transgendered people. The movement intensified in the 1980s as it became clear that governments neglected medical research and treatment for people sick with AIDS, which they dismissed as a “gay disease.” The organization Act Up’s advocacy campaign for AIDS research created a powerful symbol using the words “Silence = Death” inside a pink triangle to represent the AIDS crisis.

By the 1990s gay rights activists had broadened their efforts to challenge discrimination in employment, education, and public life. In 1995 Canada became the first country to allow same-sex marriage. In the ensuing years many European countries followed suit. But the legalization of same-sex marriage was not only a Western achievement: by 2013 Argentina, South Africa, Ecuador, and Uruguay had legalized same-sex marriage, while many other nations provided legal protections for families that stopped shy of marriage. Argentina led the way in legal support for transgendered people and made sexual reassignment surgery a legal right in 2012.