Justice Ruth Bader Ginsburg will become the first Supreme Court member to conduct a same-sex marriage ceremony Saturday when she officiates at the Washington wedding of Kennedy Center President Michael M. Kaiser.

The gala wedding of Kaiser and economist John Roberts at the performing arts center brings together the nation’s highest court and the capital’s high society and will mark a new milepost in the recognition of same-sex unions.

Such marriages were virtually unheard of a little more than a decade ago but now are legal in the nation’s capital, 13 states and in all or part of 17 other countries. After victories at the Supreme Court earlier this summer, a wave of litigation is challenging bans on same-sex marriages in states where they remain prohibited.