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