This research brief analyzes the impact of the US Supreme Court’s decisions in Windsor v. United States (June 2013) and Obergefell v. Hodges (June 2015) on marriage by same-sex couples. In 2013, the year that the Windsor ruling was issued, an estimated 230,000 same-sex couples were married, 21% of all same-sex couples. By June 2015, when Obergefell was decided, 390,000 same-sex couples were married, 38% of all same-sex couples. As of October 2015, 486,000 same-sex couples were married, or 45% of all same-sex couples. The legal benefits and obligations of marriage now support these married couples, more than a quarter of whom are raising children, and the visibility of these families will likely continue to accelerate public support for marriage equality in the United States.