So yes, marriage will change. Or rather, it will change again. The fact is, there is no such thing as traditional marriage. In various places and at various points in human history, marriage has been a means by which young children were betrothed, uniting royal houses and sealing alliances between nations. In the Bible, it was a union that sometimes took place between a man and his dead brother’s widow, or between one man and several wives. It has been a vehicle for the orderly transfer of property from one generation of males to the next; the test by which children were deemed legitimate or bastard; a privilege not available to black Americans; something parents arranged for their adult children; a contract under which women, legally, ceased to exist. Well into the 19th century, the British common-law concept of “unity of person” meant a woman became her husband when she married, giving up her legal standing and the right to own property or control her own wages.
Many of these strictures have already loosened. Child marriage is today seen by most people as the human-rights violation that it is. The Married Women’s Property Acts guaranteed that a woman could get married and remain a legally recognized human being. The Supreme Court’s decision in Loving v. Virginia did away with state bans on interracial marriage. By making it easier to dissolve marriage, no-fault divorce helped ensure that unions need not be lifelong. The recent surge in single parenthood, combined with an aging population, has unyoked marriage and child-rearing. History shows that marriage evolves over time. We have every reason to believe that same-sex marriage will contribute to its continued evolution.