Same-sex marriage has been legalized in a growing number of states around the country. But under federal law, marriage is still defined as a union between a man and a women. If the U.S. ever does legalize same-sex marriage nationally, it won’t be the first country in the world to do so. Not even close. In fact, there are currently 10 nations around the world where same-sex marriage is universally legal. Explore this map to see where and since when.