Former President Barack Obama on Tuesday remembered Edith Windsor, who passed in Manhattan at the age of 88.

Windsor successfully challenged the Defense of Marriage Act (DOMA), a law that prohibited federal agencies from recognizing the legal marriages of gay and lesbian couples. The Supreme Court's 2013 ruling paved the way for Obergefell, which found that gay couples have a constitutional right to marry.

(Related: Edith Windsor, plaintiff in Supreme Court case that struck down DOMA, dies at 88.)

Obama released the following statement on Facebook.

America’s long journey towards equality has been guided by countless small acts of persistence, and fueled by the stubborn willingness of quiet heroes to speak out for what’s right. Few were as small in stature as Edie Windsor – and few made as big a difference to America.

I had the privilege to speak with Edie a few days ago, and to tell her one more time what a difference she made to this country we love. She was engaged to her partner, Thea, for forty years. After a wedding in Canada, they were married for less than two.

But federal law didn’t recognize a marriage like theirs as valid – which meant that they were denied certain federal rights and benefits that other married couples enjoyed. And when Thea passed away, Edie spoke up – not for special treatment, but for equal treatment – so that other legally married same-sex couples could enjoy the same federal rights and benefits as anyone else.

In my second inaugural address, I said that if we are truly created equal, then surely the love we commit to one another must be equal as well. And because people like Edie stood up, my administration stopped defending the so-called Defense of Marriage Act in the courts.

The day that the Supreme Court issued its 2013 ruling in United States v. Windsor was a great day for Edie, and a great day for America – a victory for human decency, equality, freedom, and justice. And I called Edie that day to congratulate her.

Two years later, to the day, we took another step forward on our journey as the Supreme Court recognized a Constitutional guarantee of marriage equality. It was a victory for families, and for the principle that all of us should be treated equally, regardless of who we are or who we love.

I thought about Edie that day. I thought about all the millions of quiet heroes across the decades whose countless small acts of courage slowly made an entire country realize that love is love – and who, in the process, made us all more free. They deserve our gratitude. And so does Edie. Michelle and I offer our condolences to her wife, Judith, and to all who loved and looked up to Edie Windsor.