Published: July 13, 2012

When President Obama became the first American president to publicly support same-sex marriage, he acknowledged a trend in American culture: that marriage–the laws, as well as social conventions and expectations surrounding it–have long been subject to change.

In this hour of BackStory, we commit ourselves to unpacking the history of the institution and its shifting definitions in America. By taking a look at everything from the founder of couples counseling to the town that was Vegas before Vegas was Vegas, the History Guys ask who’s been allowed to marry whom, and consider what has been at stake when couples break the rules. More than that, why have some disagreements about marriage melted away as others have become more contentious? And how have the rules we make about marriage changed the shapes of our families and influenced our society?