Their marriages were long in coming—and tragically shortened by illness. But for two same-sex couples, their unions became crucial legal litmus tests that would change the course of LGBTQ rights in America.

It was the union of Edith (“Edie”) Windsor and Thea Spyer, together for 40 years before they legally married, which prompted the 2013 United States v. Windsor ruling—which mandated federal spousal benefits for same-sex couples. Two years later, the Obergefell v. Hodges decision would forever alter the definition of marriage in the U.S. It validated, once and for all, the union of Jim Obergefell and John Arthur, a Cincinnati couple who had raced a deadly disease to wed on an airport tarmac, only to have their marriage nullified by restrictive state law.

READ MORE: The Supreme Court Rulings That Have Shaped Gay Rights in America

In 2007, a terminal diagnosis prompted Edie Windsor and Thea Spyer to fly to Toronto, Canada—where, surrounded by a handful of friends, they were married by Canada’s first openly gay judge. Spyer, wheelchair-bound, was dressed in all black; Windsor, in all white, sat on her lap.

Their love story began in 1963 when Windsor, who had recently divorced and moved to New York to attend graduate school in mathematics, asked a friend to bring her to a spot where lesbians hung out. They went to a Greenwich Village restaurant called Portofino, where she was introduced to Spyer, a young psychologist. Later that night, they ended up at Spyer’s apartment with a bunch of friends.

“She danced a hole into the bottom of her stockings,” Spyer recounted in the 2009 documentary “Edie & Thea: A Very Long Engagement.”

Windsor was interested in an exclusive relationship immediately, but felt conflicted. Given the social pressures of the time, she struggled with her sexuality and even attended group therapy to try and help her live a “straight” life. Spyer, meanwhile, wanted to play the field.

READ MORE: Women Got 'Married' Long Before Gay Marriage

It took a bold move on Windsor’s part to interest Spyer in a committed relationship: After learning her love interest would be in the Hamptons one weekend, Windsor defied her therapist’s advice and showed up there the next day. Seeing Spyer, Windsor asked, “Is your dance card filled?” The response: “It is now.” The next summer, they rented a house together.

The years that followed were a blur of traveling, dancing, hosting parties and passionate love. Both wanted children, but at the time that was unthinkable. In 1967, with no legal ability to follow through on her desire, Spyer proposed to Windsor, presenting her with an engagement pin designed as a circle of diamonds. (Windsor worked at IBM, where a more traditional ring would attract questions she didn’t want to answer.) Spyer couldn’t even finish her sentence before Windsor was shouting “Yes!”

Ten years later, a 45-year-old Spyer was diagnosed with chronic progressive multiple sclerosis; she eventually became a quadriplegic. Windsor retired and cared for her full-time.

In 1993, when New York passed its domestic-partnership law, the two women officially became partners. Over a decade later, when doctors told Spyer she had one year left to live, they decided to legally marry in Canada.

READ MORE: How Ellen's 'Puppy Episode' Influenced Hollywood—and America

Filmmakers who accompanied the couple that day related their love story in the 2009 documentary “Edie & Thea: A Very Long Engagement.” In the film, the couple can be seen sitting, side-by-side, as the wedding approached. “We’re both dying to say ‘with this ring, I thee wed,’ ” Windsor explains, beaming. During the ceremony, Spyer, unable to move her arms, found her eyes filling with tears; Windsor gently wiped them away.

In the documentary, the two women can be seen doing what they had always loved—zipping around the dance floor together—now with Spyer in a wheelchair and Windsor on her lap.

On February 2009, Spyer died at home. Two months later, her widow suffered a heart attack, later calling it “broken-heart syndrome.”

As Windsor grieved, she was hit with $363,053 in federal inheritance taxes on her wife’s estate. Because the federal government didn’t recognize her marriage, she wasn’t eligible for the estate-tax exemption afforded to spouses. With the help of prominent civil-rights lawyer Roberta Kalpan, Windsor filed a lawsuit in 2010.

The case made its way to the Supreme Court where, on June 26, 2013, the justices issued a 5–4 decision declaring Section 3 of the Defense Of Marriage Act (DOMA) unconstitutional—and mandating that federal spousal benefits be granted to same-sex couples. Fifty years after Spyer and Windsor’s love story began, it fundamentally changed LGBT rights.

READ MORE: What Happened at the Stonewall Riots? A Timeline of the 1969 Uprising

The day the United States v. Windsor ruling was announced, a couple in Cincinnati, who had been together for 20 years, decided to wed.

Jim Obergefell and John Arthur would joke that it was love at third sight. Once they discovered the chemistry on their third date, they never separated. They bought a home in Cincinnati, often worked together at IT services and client-management firms, and shared many hobbies.

Obergefell and Arthur weren’t activists; they concentrated on working hard and being solid citizens. Almost 20 years into their relationship, in the winter of 2011, Obergefell noticed something unusual: His partner’s foot was slapping the ground as he walked, and he was starting to fall. Doctors diagnosed Amyotrophic Lateral Sclerosis, or ALS, more commonly known as Lou Gehrig’s disease. It progressed fast: Within two years, he was confined to a bed and Obergefell took on the role of caretaker.

They had discussed marriage throughout their years together, but had no interest in doing it symbolically; they wanted it to mean something legally. Once the Supreme Court handed down the United States v. Windsor decision, Obergefell saw a glimmer of hope—and proposed. With DOMA defeated, their marriage could be legally binding.

But in Ohio, it wasn’t that simple. The state didn’t recognize same-sex marriages. In fact, in 2004 the state’s constitution was amended to prohibit the recognition of same-sex marriages.

They needed to go to a state that recognized same-sex unions, but Arthur wasn’t well enough to travel to obtain a marriage license in another state. Obergefell began to search for a nearby state where gay marriage was legal and where only one partner was required to apply for the license.

READ MORE: When Hollywood Studios Married Off Gay Stars to Keep Their Sexuality a Secret

Maryland fit the bill. To get his wheelchair-bound partner there, Obergefell turned to his friends and family on Facebook, who donated $13,000 to help him secure a medical plane and a nurse to fly them there. On July 11, 2013, one of Arthur’s aunts, Paulette Roberts (who had gotten herself ordained) married the two longtime partners on the tarmac at the Baltimore-Washington International Airport. Arthur couldn’t leave the plane.

From that moment on Obergefell says the couple never uttered two sentences without the word “husband” in them. Marriage made all the difference in the world.

When a neighbor mentioned their union to a local civil-rights attorney, Al Gerhardstein, he advised them of the legal complications ahead. Under current Ohio law, when Arthur died, Obergefell would not be listed as his legal spouse on his death certificate.

Just over a week after their wedding, Obergefell filed a lawsuit, with Ohio Governor John Kasich as the lead defendant. The district court ruled in Obergefell’s favor. When Arthur died three months after their wedding, in late 2013, his death certificate listed Jim Obergefell as his spouse.

READ MORE: For Centuries, Blackmail Was a Tool Used to Intimidate Gay Men

Officials in five states—Indiana, Oklahoma, Virginia, Wisconsin, and Utah—appealed to the Supreme Court to have same-sex marriage banned. Each time, the Supreme Court refused to hear the cases, sending the issue back to the states. In November 2014, the U.S. 6th Circuit Court of Appeals upheld bans on same-sex marriage in six cases, from four states—including Ohio, where Arthur’s death certificate would be updated to say “single.”

It was the first time since the Windsor decision that a federal appeals judge had ruled against gay marriage. Already grieving, Obergefell was devastated that the state was invalidating their marriage.

For Obergefell, the quest was a simple one: In his husband’s death he didn’t want their marriage to be erased. He appealed, once again, to the Supreme Court. Now that the circuit courts were split, the Supreme Court agreed to hear cases from each state within the 6th Circuit—Kentucky, Michigan, Tennessee and Ohio.

The Obergefell v. Hodges decision came on June 26, 2015—the second anniversary of the ruling of United States v. Windsor. In a 5–4 decision, the justices declared that the fundamental right to marry is guaranteed to same-sex couples.

Theirs was a love that spanned 20 years, a terminal diagnosis, marriage on a tarmac and ultimately one partner’s premature death. Like Edie Windsor, Jim Obergefell was asking for basic spousal rights. And like her, he profoundly changed the marriage laws of the United States.