New York: Gay rights activist Edith Windsor, whose same-sex marriage fight led to a landmark US ruling, has died aged 88.
Her death was confirmed to the New York Times by her wife Judith Kasen-Windsor. She died in New York.
"The world lost a tiny but tough-as-nails fighter for freedom, justice and equality," the BBC quoted Kasen-Windsor as saying.
"Edie was the light of my life. She will always be the light for the LGBTQ community, which she loved so much and which loved her right back," she added.
Windsor`s Supreme Court case struck down the Defence of Marriage Act in 2013, granting same-sex married couples federal recognition for the first time.
She had sued the US government after being ordered to pay $363,053 in federal estate tax after her previous wife, Thea Spyer, died. The couple had been partners for 44 years and had married in Canada in 2007.
Windsor, known as Edie, argued that the provision of the law which defined marriage as between a man and a woman prevented her from getting a tax deduction due to married couples - and was "unconstitutional".
In the landmark 2013 ruling, the US Supreme Court agreed - and that decision became the basis for a wave of further court rulings increasing the rights of same-sex couples.
In 2015, another crucial Supreme Court ruling gave same-sex couples the right to marry.
Former US Presidents Bill Clinton and Barack Obama also paid their tributes.
"Few were as small in stature as Edie Windsor - and few made as big a difference to America," Obama said. While Clinton tweeted: "In standing up for herself, Edie also stood up for millions of Americans..."