Same-sex marriage (also called gay marriage or homosexual marriage) is the union of two people of the same gender. Gay and lesbian couples experience discrimination on both the personal and the legal level; same-sex marriage was illegal in most of the United States until 2015. Although the US Constitution does not explicitly prohibit same-sex marriages, the federal government, until that time, largely did not recognize the validity of such marriages. Because it is not dealt with directly in the Constitution, there had been several cases brought by gay rights activists and homosexual couples, questioning the legality of the de facto ban on same-sex marriage. These suits, as well as legislative and voter action, resulted in some states and localities legalizing same-sex marriage. Opponents of same-sex marriage have supported a proposed constitutional amendment that would define marriage as a union between one man and one woman.
Salem Press Encyclopedia, 2016