She died at the age of 88. In 2007 Windsor had married her partner Thea Clara Spyer in Canada, where such marriages were legal, after being together for 40 years. They moved to the US later and Spyer died in 2009 but DOMA prevented Windsor from claiming the federal tax exemption for inheritances that are available to spouses. So she sued to overturn DOMA. Her case United States v. Windsor, that she won 5-4 in the US Supreme Court in 2013, helped pave the way for same-sex marriages becoming legalized two years later. The court ruled that the Defense of Marriage Act (DOMA) that, among other things, denied federal tax benefits to lawfully married same-sex couples, was unconstitutional.
In his majority opinion in the Windsor case, justice Anthony Kennedy wrote:
The class to which DOMA directs its restrictions and restraints are those persons who are joined in same-sex marriages made lawful by the State. DOMA singles out a class of persons deemed by a State entitled to recognition and protection to enhance their own liberty. It imposes a disability on the class by refusing to acknowledge a status the State finds to be dignified and proper. DOMA instructs all federal officials, and indeed all persons with whom same-sex couples interact, including their own children, that their marriage is less worthy than the marriages of others. The federal statute is invalid, for no legitimate purpose overcomes the purpose and effect to disparage and injure those whom the State, by its marriage laws, sought to protect in personhood and dignity. By seeking to displace this protection and treating those persons as living in marriages less respected than others, the federal statute is in violation of the Fifth Amendment. This opinion and its holding are confined to those lawful marriages.”
Interestingly, on hearing the news Bill Clinton tweeted, “In standing up for herself, Edie also stood up for millions of Americans and their rights. May she rest in peace.” He quietly ignored the fact that in one of the most craven pandering acts of his presidency (and there were many), he was the one who signed the infamous DOMA into law.