Activists marched through Boston Wednesday afternoon to stand against racial injustice, travelling a path that illuminated the long history of Black Bostonians' fight against racism.

Led by Black Boston 2020 and Black Future Project, two grass-roots organizations founded by young activists, demonstrators set off from Boston Common on a march that turned downtown Boston into both a protest site and a classroom.

Donning masks due to the COVID-19 pandemic, more than 100 people held signs reading “Boston legalized slavery first’’ and “Black abolitionists lived in Beacon Hill.’’ Before marching, protesters gathered in a circle on the Common to share hand sanitizer, markers, and poster board, and stories about the Black activist history they said they had not learned in school.

They processed through the city for just over two hours, frequently stopping traffic and pausing at landmarks along the route for lessons on Black Bostonian history and the city’s ongoing struggles with race and racism.

The march’s leaders said they hoped to reinvigorate the young people who showed up in force to May and June rallies, when a spate of police killings of Black Americans sparked protests across the country.

After a relatively quiet summer, organizers said it’s time to remind their peers — and people in power — why they marched.

“Protest is about more than the death of one person. It’s about challenging a whole system,’’ said Hodan Hashi, one of the founders of Black Boston 2020, a group of college-age activists who led one of the city’s earliest and largest protests in May. "For us, it was really important to do something towards the end of the summer to show that people aren’t letting up. This isn’t something that people are going to forget about. They’re in it for the long haul.’’

“The consistent activism and marching and pushing for change is new for our generation. Momentum has to be continuously stirred up,’’ said Deanna Marshall, a cofounder of the Black Future Project. Marshall compared Boston, where she was born and raised, to Los Angeles, where she has lived since 2017 and founded Black Future Project, which leads large-scale demonstrations and mentors young activists.

“In Los Angeles, the protests are still ongoing. The police brutalization is still ongoing. ... So there’s a lot of pushback that drives people to keep on going,’’ Marshall said. “[In Boston] there are a lot of folks wondering what happened. Is it that things are cured in Boston and we don’t need to march anymore, or that people got tired?’’

The march drew about 120 demonstrators. Nearly all of the marchers were in their teens and twenties. The group was racially diverse and energetic, but turnout was only a fraction of the crowds Black Boston 2020 and other groups led down Boston streets just a few short months ago.

Still, organizers said they felt they had accomplished their core mission — educating young people about the city they live in.

“Our measures are in quality, not in quantity,“ said Yaritza Dudley, a Black Boston 2020 organizer. “I think things turned out pretty powerfully. The whole purpose of this action was education. It was very intentional, and I think that the message stuck.’’

Protesters gathered at 4 p.m. near the Park Street T station, where organizers instructed demonstrators to march peacefully and avoid engaging police. From there, they marched through downtown, with stops at the Museum of African American History on Joy Street, the State House, King’s Chapel, City Hall, and Faneuil Hall.

Along the route, protesters shut down traffic at several busy intersections, including along Beacon, Tremont, and Congress streets. At each stop, organizers shared snippets from the city’s history. Rather than the familiar stories of Revolutionary heroism, organizers spoke of Boston’s history of slavery, colonization, and violent resistance to school desegregation.

“Citizens cannot maintain both ignorance and freedom,’’ said Marshall, quoting education pioneer and Massachusetts native Horace Mann. “That is why we are learning together today about the full history of Black Bostonians and about the full history of our nation’s founding fathers, the vast majority of whom were slave owners and proponents of slavery.’’

’’This is what we don’t hear on the Freedom Trail,’’ said James Butler, a Black Future Project organizer.

The march was meant to mirror popular Colonial walking tours, as well as to challenge a version of Boston history that organizers said has minimized Black Bostonians’ contributions and the racism they have endured.

A poster for the event confronts this history squarely. Front and center is a photo of an 1851 abolitionist flier warning Black Bostonians that under the Fugitive Slave Act passed in 1850, local police could detain them and — if they were found to have escaped enslavement — send them back to bondage.

“Caution!! Colored people of Boston, one & all," the flier reads. “You are hereby respectfully cautioned and advised, to avoid conversing with the watchmen and police officers of Boston, for since the recent order of the mayor and aldermen, they are empowered to act as kidnappers and slave catchers.’’

This flier, the Black Future Project and Black Boston 2020 poster says, represents “our true story.’’ “Racist America has its roots in Boston,’’ the poster continues.

“There’s this thing about Boston where people think it’s really progressive,’’ Hashi said. But history and the current lived conditions of Black communities show otherwise, she said.

Throughout the march, which ended at 6:30 p.m. in front of Faneuil Hall, attendees remained attentive and energetic. They loudly chanted along to cries of “No justice, no peace’’ and “Whose streets? Our Streets’’ while marching and quickly fell quiet when organizers paused to share history lessons.

Marshall called on demonstrators — many of them white college students — to challenge their universities to teach more inclusive histories and address the gentrification she said they helped to create.

Organizers said that teaching their peers more about the past will empower them to demand a better future.

“The only way we can talk about how we can change systems in this city is to really understand what systems were put in place, why they were put in place, who put them in place and how that directly impacts Black people in this city," Hashi said. "Until we start having that conversation, I don’t really see how we can move on.’’

Dasia Moore can be reached at dasia.moore@globe.com.