 Same-sex marriage in Maryland has been on the upswing since a decade ago when it was first legalized. The U.S. Census Bureau estimates there were about 4,400 same-sex married couples in Maryland in 2012. That's the year before the state made it legal. That number grew to more than 10,000 by 2015 when the Supreme Court ruled marriage a fundamental right that could not be denied to same-sex couples.