When Michael Mizell-Nelson was in high school, he’d ride the streetcar from his parents’ home on Newcomb Boulevard to Benjamin Franklin High School on South Carrollton Avenue.

The commute, unspectacular to some, was a seminal experience in the career of the future University of New Orleans history professor, for it was during those trips that he first became intrigued with the stories of his fellow riders.

It was his passion for finding truth and heroism in the lives of everyday New Orleanians that made him a beloved figure in the classroom and outside of it.

Mizell-Nelson died Monday of cancer. He was 49.

A native New Orleanian, Mizell-Nelson was described by friends, co-workers and family members as a “people’s historian,” whose bottom-up philosophy of telling history brought forth evocative narratives that touched a wide swath of social-justice issues.

“He was one of the kindest, gentlest men I have ever known, who was incredibly ardent about everything from race equality to gender equality to preserving the New Orleans po-boy sandwich,” said Poppy Tooker, a food journalist and host of the WWNO Radio show “Louisiana Eats.”

A graduate of Tulane University, Mizell-Nelson taught at Delgado Community College before being hired by UNO in 2004.

It was his research on the po-boy that provided the definitive story on the origin of the ever-popular New Orleans sandwich.

Mizell-Nelson tracked the po-boy’s birth to a 1929 strike of streetcar workers. Brothers Bennie and Clovis Martin sympathized with those on strike and offered them free sandwiches from their French Market store, Martin Brothers’ Coffee Stand and Restaurant.

Mizell-Nelson located a letter from the Martins, which stated, “Whenever we saw one of the striking men coming, one of us would say, ‘Here comes another poor boy.’ ”

The story was chronicled in his film “Streetcar Stories,” which was produced in 1995 and aired on PBS.

Lawrence Powell, a professor emeritus of history at Tulane, oversaw Mizell-Nelson’s dissertation.

Powell described him as a focused, persistent student who latched onto subjects with local flavor that chronicled the experiences of “the folks who don’t leave manuscripts and letters.”

He also touted Mizell-Nelson’s ability to create collaborative projects between different institutions.

In the wake of Hurricane Katrina, he helped develop the Hurricane Digital Memory Bank, an online archive of more than 25,000 photos, oral histories and other artifacts from hurricanes Katrina and Rita.

Mizell-Nelson also was co-director for neworleanshistorical.org, a Web and mobile platform for sharing stories about New Orleans.

Richard McCarthy, a friend of Mizell-Nelson’s, said the historian’s discipline and patience also paid off in his activism.

The two were student activists together while members of the group Truth About Duke, which opposed the 1991 gubernatorial campaign of state Rep. David Duke.

Duke was a former grand wizard of the Knights of the Ku Klux Klan and had made it to a runoff against Edwin Edwards.

McCarthy said Mizell-Nelson decided the way to sway votes away from Duke was to create pamphlets that showed the fallacy of his proposals for balancing the state budget.

“We were able to zero in on actual issues because Michael was so exact and detailed,” McCarthy said. “We would pass (the pamphlets) out outside of the Saints games.”

According to Mizell-Nelson’s wife, Cathe Mizell-Nelson, the pamphlets were eventually utilized by the Edwards campaign.

She described her husband as a man with ceaseless energy who was a loving father and husband.

“Sometimes I felt so exasperated by the endless to-do lists that I just wanted to shout, ‘Stop having ideas!’ ” she said. “But I didn’t because that and his wry sense of humor are what drew me to him in the first place.”

Besides his wife, survivors include two children, Arlo and Keely Mizell, and a sister, Tracy Moore.

Funeral arrangements are incomplete, but a memorial service likely will be held at UNO in January.