The first lawsuits involving same-sex marriage started in the 1970s, bringing the question of civil marriage rights for same-sex couples to public attention. Many of these lawsuits were unsuccessful.
On February 12, 2004, the first same-sex marriage in the United States happened in San Francisco, California. Del Martin and Phyllis Lyon become the first gay couple to marry and receive official recognition after being together for 50 years.
On May 17, 2004, Massachusetts became the first state and sixth jurisdiction in the world to legalize same-sex marriage. Following this, opponents of same-sex marriage began tightening restrictions on marriage, with a number of states approving state constitutional amendments specifically defining marriage as the union of one man and one woman.
In 2008, California and Connecticut both legalized same-sex marriage, followed by Iowa, Vermont, and New Hampshire. Up until 2012, legalization came through state courts, the enactment of state legislation, or the result of the decisions of federal courts. On November 6, 2012, Maine, Maryland and Washington became the first states to legalize same-sex marriage through popular vote.
On June 26, 2015, the Supreme Court ruled that it is unconstitutional for states to ban same-sex marriages in the landmark case Obergefell v. Hodges. However, not all state legislatures are abiding by this decision, and have enacted constitutional or statutory bans on same-sex marriage, known as “Defense of Marriage” Acts.
37 states have legalized gay marriage, with restrictions in Kansas, Missouri, and Alabama. Thirteen states still have a ban on same-sex marriage, but 8 of those states have rulings in favor of allowing same-sex marriage.
The following 37 states (and the District of Columbia) have legalized same-sex marriage:
The following 13 states have not legalized same-sex marriage: