The Defense of Marriage Act (DOMA) was a United States federal law enacted in 1996 that defined marriage for the purposes of federal law as the union of one man and one woman, thereby denying federal recognition and benefits to same-sex marriages. It also permitted states to refuse to recognize same-sex marriages legally performed in other states under the Full Faith and Credit Clause of the U.S. Constitution. The law's purpose was to address concerns over the potential nationwide legalization of same-sex marriage following a 1993 Hawaii court ruling suggesting it might occur there. Its impact included widespread denial of federal benefits such as Social Security survivor benefits, tax advantages, and immigration rights to same-sex couples. In 2013, the U.S. Supreme Court ruled in United States v. Windsor that Section 3 of DOMA was unconstitutional under the Due Process Clause, invalidating the federal definition of marriage and restoring federal benefits to legally married same-sex couples. Section 2, regarding state non-recognition, remains in effect but has limited practical impact post-Obergefell v. Hodges (2015), which mandated nationwide same-sex marriage recognition.