On the night of March 11, 1972, thousands of Black Americans from around the country — Democrats, Republicans, socialists and nationalists alike — packed into a high school gymnasium in Gary, Ind., for the first National Black Political Convention. The room brimmed with tension, as the high ideals of Black separatists were set to clash with the pragmatism of elected officials. A congressman was booed and jeered at. The NAACP denounced the convention for excluding white people. Shirley Chisholm, the first Black major-party presidential candidate, boycotted the event because the conveners couldn’t decide whether to endorse her campaign.

Then the Rev. Jesse Jackson, a close ally of the Rev. Martin Luther King Jr., took the stage. The assassinations of King and Malcolm X in the previous decade had delivered a tragic blow to the civil rights movement, and Jackson had come to Gary hoping to unify the community with a bold call.

“I don’t want to be the gray shadow of a white elephant or the gray shadow of a white donkey,” he said at the convention. “I am a Black man, and I want a Black party.”

The aspiration of an independent Black political party never came to pass, but Jackson and other leaders galvanized the thousands of activists in Gary to put forth a platform meant to address the racial inequities of the day. Tensions among different political factions would weaken the assembly over time, but historians and organizers credit the convention with helping to achieve an almost threefold increase in the number of Black elected officials in this country over the following decade.

Now, 48 years later, a group of Black Lives Matter organizers is looking to the Gary convention as a model for how they can take the energy and ideas of their protest movement into the halls of political power. On August 28, the Movement for Black Lives — a coalition of organizations founded in 2014 in response to the shooting of Michael Brown in Ferguson, Mo. — aims to engage tens of thousands of Black voters in an online Black National Convention of its own. The Black Lives Matter movement has resisted coalescing around a single leader or a hierarchy. Instead, organizers see the convention as an acknowledgment that protest is but one way to push for police and other reforms, and that electoral politics needs to play a role as well. While a handful of Black Lives Matter activists have ascended to political office, the United States still has only three Black senators and zero Black governors, despite the gains after 1972.