Twenty-one years ago today, on April 1st, 2001, The Netherlands became the first country to legalize same-sex marriage. According to The Human Rights Campaign, there are currently 31 countries around the world that have legalized same-sex marriages. Twenty-two of those countries passed this law through legislation, 3 countries of which were the result of nation-wide votes. The United States is 1 of 7 counties to permit same-sex marriage through court decisions and the remaining 2 countries passed legislation after the courts mandated them to do so. HRC notes that there are 8 additional countries that have the potential to pass legislation in 2022 to legalize same-sex marriage.
On June 26, 2015, The U.S. Supreme Court announced its decision in Obergefell v. Hodges, legalizing same-sex marriage in all 50 states. The 5-4 vote decided that a ban on same-sex marriage was unconstitutional and that the freedom to marry is protected under the Due Process and Equal Protection clauses of the 14th Amendment.
Justice Kennedy identified four "principles and traditions" that provided precedent for the protection of same-sex marriage under the Due Process Clause of the Fourteenth Amendment:
Personal choice in marriage is ‘inherent in the concept of individual autonomy.’
Marriage is ‘fundamental because it supports a two-person union unlike any other in its importance to the committed individuals.’
Marriage ‘safeguards children and families and thus draws meaning from related rights of childrearing, procreation, and education.’
Marriage ‘is a keystone of [the country]'s social order’ and there ‘is no difference between same- and opposite-sex couples with respect to this principle.’"
Human Rights Campaign: Link
Obergefell v. Hodges - Ballotpedia Link