Jeremy Brecher is recognized as a historian, documentary filmmaker, activist, and author, with a significant body of work focusing on labor and social movements. His career includes co-founding the magazine and pamphlet series Root & Branch, which explored the tradition of workers' councils.

Brecher has been a key figure in "history from below" initiatives, engaging communities in historical projects. This approach has involved extensive oral history collection and the creation of public history products, such as documentaries, radio programs, and museum exhibits, often in collaboration with community members. His work in public history in Connecticut, supported by various humanities councils, has been recognized for its quality and contribution to the state's self-definition.

Beyond labor and public history, Brecher has engaged with global labor issues through the organization Global Labor Strategies and has become a prominent voice in climate activism, influenced by early awareness of global warming. His activism has also included direct action and organizing efforts related to war resistance and environmental concerns.

Jeremy Brecher's early work involved co-founding Root & Branch in 1969, a publication and pamphlet series that drew upon the tradition of workers' councils and adapted these ideas for contemporary America. This initiative led to the 1975 collection, Root & Branch: The Rise of the Workers’ Movements. He has since pioneered "history from below," a method that fosters "shared authority" between professional historians and the communities they study. This approach is exemplified by numerous community-based historical and cultural projects, particularly in the Naugatuck Valley. These projects, often funded by humanities councils, involved significant participation from workers and community members in documenting their own histories through interviews and archival contributions. His work has been praised for its innovative use of oral history to capture individuals' own interpretations of their past.

Brecher has had a substantial career in public history and media production, notably serving as a Humanities Scholar-in-Residence at Connecticut Public Television and Radio from 1989 to 2001. During this time, he wrote scripts for and co-produced several documentaries, including "The Roots of Roe," "Schools in Black and White," and "The Amistad Revolt." He also developed and supervised "The Connecticut Experience," a documentary series praised for its comprehensive exploration of state topics and effective use of the humanities. Furthermore, he produced and hosted "Remembering Connecticut" for Connecticut Public Radio, a long-running series recognized for its historical depth and accessibility. His contributions to public history have earned him accolades, including the Connecticut Humanities Council's Wilbur Cross Award for Humanities Scholar of the Year in 2000.

In 2005, Brecher co-founded Global Labor Strategies (GLS) with Brendan Smith, an organization aimed at fostering global labor solidarity through research and advocacy. GLS engaged in significant international work, notably organizing protests against corporate opposition to China's Labor Contract Law, which led to pressure from international unions and human rights groups. Brecher's awareness of environmental issues began in the early 1970s, leading him to co-author "Common Sense for Hard Times," which addressed environmental degradation. In recent years, he has become a prominent advocate for climate protection, co-founding the Labor Network for Sustainability and writing extensively on climate issues, including "Against Doom: A Climate Insurgency Manual" and "The Green New Deal from Below." His activism has included participation in protests, such as the KXL pipeline demonstrations, where he was arrested.