Same-sex marriage in the United States

The legal recognition of same-sex marriage in the United States expanded from one state in 2004 (Massachusetts) to all fifty states in 2015 through various court rulings, state legislation, and direct popular vote. States have separate marriage laws, which must adhere to rulings by the Supreme Court of the United States that recognize marriage as a fundamental right guaranteed by both the Due Process Clause and the Equal Protection Clause of the Fourteenth Amendment to the United States Constitution, as first established in the 1967 landmark civil rights case of Loving v. Virginia. Civil rights campaigning in support of marriage without distinction as to sex or sexual orientation began in the 1970s. In 1972, the later overturned Baker v. Nelson saw the Supreme Court of the United States decline to become involved. The issue became prominent from around 1993, when the Supreme Court of Hawaii ruled in Baehr v. Lewin that...