Marriage, wrote historian William Alexander in 1779, “is so far from having been an institution, fixed by permanent and unalterable laws, that it has been continually varying in every period, and in every country.”1 Alexander’s recognition of the historical contingency of marriage is being confirmed by a growing body of scholarship exploring marriage, sexuality, and domestic unions across time and space. The next annual meeting of the AHA, to be held in San Diego in January 2010, will feature a threaded miniconference, “Historical Perspectives on Same-Sex Marriage,” which will highlight this recent scholarship and explore its implications for the contemporary debate over same-sex marriage. Supporters of Proposition 8, which in November 2008 banned same-sex marriage in California, argue that Prop 8 “restores the definition of marriage to what ... human history has understood marriage to be.”2 “Historical Perspectives on Same-Sex Marriage” will challenge this ill-informed misuse of the past by presenting a history that does justice to the complexity of human experience over time. At the San Diego meeting, one or more sessions on this topic will meet during each major time slot of the four-day convention, and a special presidential plenary on the theme has also been scheduled for Saturday evening....