It is no small feat for lawyers or a law firm to topple a federal law that writes “inequality into the entire United States Code,” in the words of Justice Anthony Kennedy. But that is exactly what Roberta Kaplan and Paul, Weiss, Rifkind, Wharton & Garrison achieved with the U.S. Supreme Court’s landmark decision last June in United States v. Windsor.

Kaplan, a firm partner, represented Edith Windsor in her challenge to the provision in the Defense of Marriage Act defining marriage as the union between a man and a woman. Windsor was legally married to Thea Spyer. When Spyer died in 2009, leaving her estate to Windsor, the widow was smacked with federal estate taxes of nearly $400,000 — taxes she would not have had to pay had she married a man.