For generations of Cambridge students, Larry Aaronson was the kind of teacher whose lessons did not necessarily end when the bell rang — or even when you graduated.

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Aaronson, a longtime Cambridge Rindge and Latin School social studies teacher, activist and ubiquitous photographer of Cambridge life, died Aug. 1 at age 85 at the Neville Center at Fresh Pond in Cambridge. He had been battling chronic lymphoblastic leukemia. Over three decades at CRLS, he taught thousands of students to look at American history critically, question accepted narratives and consider the experiences of people who too often appeared only at the margins of traditional textbooks.

People were at the center of his life, and many of them felt the same way about him. A tribute page has drawn scores of submissions and more than 700 comments have been left on Aaronson’s Facebook page.

“One thing that was amazing to witness in the last few weeks and months of his life were how many people showed up for Larry,” said Abby Brown, a former student of Aaronson’s who lives in Strawberry Hill. “He gave so much for so long to the community and the community gave it back at the end, when it mattered most. During his last week, his bed was surrounded from morning to night with former students, colleagues, parents of former students, friends, and community members.”

She said on his final night, 11 people, family members, friends and former students, gathered “around his bed talking, telling Larry stories, and singing. It was remarkable – he was teaching us about community right up to his death – forever the teacher!”

Born Lawrence Samuel Aaronson in Washington, D.C., on Aug. 31, 1940, Aaronson attended Sidwell Friends School and Earlham College before earning master’s degrees from Johns Hopkins University’s School of Advanced International Studies and the Columbia University Graduate School of Journalism. Journalism initially seemed a possible career, but teaching ultimately became his life’s work.

After beginning as a teacher in Washington in the 1960s, Aaronson came to Cambridge to pursue doctoral studies at Harvard. He left the program for the classroom, teaching at Cambridge’s alternative Group School before joining CRLS in 1977. He remained there until his retirement in 2007, along the way chairing the school’s Social Studies Department.

Aaronson’s classroom reflected the progressive politics that informed much of his life outside it. He taught Howard Zinn’s “A People’s History of the United States” and put civil rights, race, labor, war and social justice at the center of discussions about American history. His goal was not simply to have students memorize what happened, but to ask who was telling the story, whose voices were missing and why.

“Larry opened up the world to so many of his students,” said state Rep. Marjorie Decker, who took Aaronson’s history class as a CRLS freshman. “He gave us the critical thinking tools to understand that history wasn’t simply about the past, it was about understanding what is happening today, and recognizing that what we do today creates the kind of future we will inevitably inherit.”

Decker added that Aaronson “helped me understand that I belonged in the conversation about our history, our society, and our future.” She said his class “helped shape the trajectory of my life and the person I have become.”

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His students included some who went on to fame, including Matt Damon and  Casey Affleck, perhaps why Zinn’s book fell so demonstratively from Damon’s lips in “Good Will Hunting”—but Aaronson’s legacy was perhaps better measured by the countless former students who remained part of his life. Even decades after they left CRLS, running into “Mr. Aaronson” around Cambridge was hardly unusual.

And Aaronson was difficult to miss, because he was so often carrying a camera.

Photography became another way for him to teach, document and participate in the life of the city. He photographed CRLS students and school events as well as demonstrations, political gatherings and the everyday civic life of Cambridge. Over the years, the collection became an informal visual history of a changing city, preserving people and moments that might otherwise have disappeared from the record.

His politics similarly extended well beyond the classroom. Aaronson was a longtime advocate for peace, racial justice and progressive causes, and Cambridge honored him with a Peace and Justice Award. After his retirement, he helped establish Social Justice Works! The Aaronson Fund, which supports Cambridge public school graduates pursuing social justice work — an extension of the values he had spent decades encouraging in his students.

Aaronson also found himself unexpectedly connected to one of the darkest episodes in recent Boston history. He knew Boston Marathon bomber Dzhokhar Tsarnaev from CRLS and lived only a few houses away. When Tsarnaev was identified as a suspect in 2013, Aaronson publicly expressed his shock, remembering the young man he had known as gracious, caring and compassionate.

That moment brought national attention to a man whose life’s work was fundamentally local.

Aaronson’s Cambridge was a place to participate in, argue about, photograph and improve. He taught its youth, documented its people, and challenged students to think about the responsibilities that came with being citizens of it.

In the end, perhaps his greatest lesson was the example he set outside the classroom:  that education, civic engagement and community were not separate endeavors, but parts of the same lifelong project. 

His impact went beyond his students and his classroom, said City Councillor and CRLS alumni, Marc McGovern, “Although I wasn’t fortunate enough to have Larry as a teacher, I was fortunate to have him as a friend and mentor. Cambridge lost a true icon.”

McGovern, fellow councillor E. Denise Simmons and Mayor Sumbul Siddiqui sponsored a resolution at the Aug. 3 city council meeting recognizing Aaronson’s influence on generations of students and his commitment to public education and social justice. McGovern told Siddiqui that a key to the city that was given to Aaronson shortly before he died had been meaningful to Aaronson, saying he “did not let go of that for three days and died with it in his hand.”

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A memorial service will be held Aug. 30.