 Marriage is a legal contract, but it has long been recognized to be an anomalous one. Until the 1970s in the U.S., marriage law restricted divorce and defined the terms of marriage on the basis of gender. Marking a shift towards greater alignment of marriage with contractual principles of individualization, marriage law no longer imposes gender-specific obligations, it allows pre-nuptial property agreements, and it permits easier exit through no-fault divorce. But marriage remains (at least in U.S. federal law) an anomalous contract: “there is no written document, each party gives up its right to self-protection, the terms of the contract cannot be re-negotiated, neither party need understand its terms, it must be between two and only two people, and [until 2015, when the US Supreme Court decision in Obergefell v. Hodges established same-sex marriage in the US] these two people must be one man and one woman” (Kymlicka 1991, 88).