Marking a major civil rights turning point, the U.S. Supreme Court on Wednesday struck down Section 3 of the Defense of Marriage Act and paved the way for equal treatment under federal law of legally married same-sex couples.

Justice Anthony Kennedy, writing for a 5-4 majority, said the 1996 law, which defined marriage for federal purposes as between a man and a woman, was a violation of constitutional principles of due process and equal protection of the laws.