"She will always be light to LGBTQ community that she loved and who loved her", said Kasen, which refers to lesbian activist as a great fighter for freedom, justice and equality.
Windsor was the plaintiff in a landmark Supreme Court case that struck down parts of the federal defense of marriage act. In June 2013, the high court ruled 5-4 that this provision was unconstitutional, and that same-sex couples who were legally married are entitled to the same federal benefits as heterosexual married couples.
Windsor was represented at that battle by Robert Kaplan, who indicated, to mourn his death, have been his lawyer was " great honor" of his life.
Windsor remarried a year ago.
Several New York politicians wrote tributes to Windsor on Twitter. "I also know that her memory will be a blessing not only to every LGBT person on this planet, but to all who believe in the concept of b'tzelem elohim, or equal dignity for all".
Kaplan said the ACLU anxious that Windsor's image as a "privileged rich lady" was "not a story that's going to move people".
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Born Edith Schlain in Philadelphia on June 20, 1929, Ms. Windsor was the youngest of three children of James and Celia Schlain, Jewish immigrants from Russian Federation whose candy store and house were quarantined and subsequently foreclosed when Edith and a brother contracted polio during the Great Depression.
"Don't let anything make you feel that somehow they can beat us, because they can't", she said at the time. They began dating in 1965 and in 1967, Spyer proposed to Windsor. "When the Court struck down the so-called Defense of Marriage Act, it opened the door to nationwide marriage equality for same-sex couples".
A Very Long Engagement is now streaming for free on Here TV.
She was helping to create a new statewide gay rights group after Empire State Pride Agenda, the state's leading LGBT group, disbanded in 2015.
"Edith felt deeply the injustice of being denied the right to marry her partner of more than 40 years, and she committed herself to fighting back with determination and a smile", Moodie-Mills said. Spyer was a psychologist with a large NY practice.
Following Spyer's death, she met Judith Kasen at an LGBT rights event in 2015.
Over four decades after uprisings at Stonewall Inn, Compton's Cafeteria and Cooper's Donuts started the modern LGBTQ rights movement, Windsor became a major advocate for marriage equality.
Windsor became a full-time carer eventually after Spyer was diagnosed with multiple sclerosis in 1977. When Thea died in 2009 from a heart condition two years after we were finally married, I was heartbroken.
A public memorial will be held September 15 at at Riverside Memorial Chapel in New York City.