SAN FRANCISCO (CBS SF) — One of the pioneering civil rights activists for the LGBT movement, San Francisco resident Phyllis Lyon died of natural causes at age 95 Thursday morning, according to reports and posts on social media.

The San Francisco Bay Times published an obituary for Lyon Thursday.

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In 1955, Lyon was one of the founders of the Daughters of Bilitis, a San Francisco organization recognized as the first lesbian civil rights group in the country. Lyon was born in Tulsa, Oklahoma, in 1924 and moved to San Francisco after graduating from UC Berkeley with a journalism degree in 1946.

Lyon met her life partner and fellow Daughters of Bilitis founder Del Martin in 1950. After initially living together in the Castro District, Lyon and Martin would move to what would become their permanent residence in Noe Valley. The pair would publish the groundbreaking newsletter The Ladder, which was the first nationally distributed lesbian publication in the U.S.

In 1972, Lyon and Martin would become key early members of the Alice B. Toklas Democratic Club. The couple would co-author two influential books that would later be celebrated as cornerstone works on lesbian feminism: Lesbian/Woman and Lesbian Love and Liberation. They later became founding contributors to the free bi-weekly LGBT newspaper the San Francisco Bay Times.

The pair were famously the first couple married at San Francisco City Hall on Valentine’s Day in 2004 by then Mayor Gavin Newsom after he ordered the city clerk to begin providing marriage licenses to same-sex couples.

That marriage was voided by the California Supreme Court in August of that year. The couple married again on June 16, 2008, in the first same-sex wedding to take place in San Francisco after the California Supreme Court’s decision made same-sex unions legal. In August 2008, Martin passed away from complications of an arm-bone fracture.

Gov. Newsom acknowledged Lyon’s passing and paid tribute to her as one of his personal heroes during his daily address on the state’s response to the COVID-19 crisis Thursday afternoon.

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“Let me extend this, a little bit more personally for me still: I just learned a few hours ago that one of my heroes, Phyllis Lyon, at 95 year young passed away. Phyliss as you may know — I had the privilege of being involved in a marriage ceremony between Phyliss Lyon and Del Martin. A couple that had been together for almost half a century,” Newsom said. “The manifestation of faith, love and devotion. And yet they were denied on the basis of their sexual orientation the right to say two extraordinary words — I do.  The power and potency of those two words is profoundly significant.”

San Francisco Mayor London Breed also issued a statement on Lyon’s death.

“I am saddened by Phyllis Lyon’s passing. She was a true champion of LGBTQ rights and San Francisco was incredibly lucky to have her leadership and activism. Phyllis changed countless lives for the better. She was at the forefront of the LGBTQ rights movement — fighting for a world in which people can marry who they love and live without fear of discrimination,” the statement read.

“Through decades of organizing, activism, and writing, Phyllis helped advance civil rights protections, created robust support networks for LGBTQ people, and established political and advocacy organizations that continue her work to this day. Importantly, Phyllis was a symbol of hope and courage for San Franciscans and people around the world,” it continued. “We know that there is still more work to be done to carry forward Phyllis’s legacy of civil rights, and we will continue her fight.My thoughts and prayers are with her family and friends during this difficult time.”

Sen. Kamala Harris also praised Lyon in a tweet, calling her “an icon.”

San Francisco State Senator Scott Wiener also posted a tribute to Lyon on his Twitter account.

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Martin and Lyon also were the Founders of Lyon-Martin Women’s Health Center in San Francisco. The health center was designed for women, particularly lesbian women who needed medical care in San Francisco during a time when being outed as a lesbian could mean loss of their children, jobs, or worse.