How history supports the SCOTUS decisions on marriage

From Inside Higher Education:

Rarely have historians played as important a role in shaping the outcome of a public controversy as in the same-sex marriage cases.... 

Briefs filed with the Supreme Court by the American Historical Association and the Organization of American Historians demonstrated that far from being a static institution, marriage has profoundly changed its definition, roles, and functions, and that today's dominant marital ideal, emphasizing emotional intimacy, has nothing to do with gender. Currently, marriage's foremost public function is to distribute benefits, such as those involving health insurance, Social Security, and inheritance, making it all the more valuable for same-sex couples. 

... the historians showed that two broad themes characterize the shifting law of marriage in the United States. The first is the decline of coverture, the notion that a married woman's identity is subsumed in her husband's. A second theme is the overturning of earlier restrictions about who can marry whom.
...
Marriage today bears scant resemblance to marriage even half a century ago, when the male breadwinner family prevailed and dual-earner and single-parent households were far rarer than today. The contemporary notion of marriage as an equal, gender-neutral partnership differs markedly not only from the patriarchal and hierarchical ideals of the colonial era, but from the notion of complementary spousal roles that predominated during the age of companionate marriage that prevailed from the 1920s into the mid-1960s.
Change, not continuity, has been the hallmark of the history of marriage. ... 

History, in the same-sex marriage controversy, was not simply "preface" -- an interesting but ultimately insignificant detail in cases involving equal treatment under law. History lay bare a series of dangerously misleading assumptions -- above all, the notion that same-sex marriage deviates from a timeless, unchanging marital norm.