U.S. Legalization of Same-Sex Marriage

The availability of legally recognized same-sex marriage in the United States expanded from one state (Massachusetts) in 2004 to all fifty states in 2015 through various court rulings, state legislation, and direct popular votes. States each 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.

https://en.wikipedia.org/wiki/Same-sex_marriage_in_the_United_States