“I don’t understand why they are doing this now,” said Juan José Bautista of the event. “It’s so long ago. Why does it matter to them?”

In the years before the massacre took place, Dajabón was a sleepy outpost, isolated from the Dominican capital, Santo Domingo. In oral histories collected by researchers, Haitians and Dominicans recall a fluid border they often crossed freely and the many families and friendships formed between them.

Today, Dajabón, a city of 25,245, within a province of the same name, hums with the constant buzz of motorcycles and scooters. Border crossing are heavily guarded by the Dominican army, though it remains a magnet for child traffickers and smugglers. Officials closed the border several times after the 2010 cholera outbreak in Haiti, sparking protests.

Still, twice a week, the city becomes a major trading hub as the border opens and a cross-border informal market forms with everything from used shoes to housewares spilling into the streets. The market, which generates more than $1 million weekly in trade according to a 2007 study by Solidaridad Fronteriza, a local non-governmental organization, underscores the economic connection that still thrives here.

Cynthia Carrion, a New York-born Dominican and a principal organizer, said some have criticized her for marking something that they said was of little relevance today.

“The reason we’re doing this is not to open old wounds, but to say that the same tensions and ignorance that brought about the massacre are still here today,” Carrion said. “The wounds haven’t had a chance to heal because it’s been forgotten.”

The event, however, is seen as a turning point in the Dominican government’s treatment of Haitians and Dominicans of Haitian descent.

Haitians are routinely rounded up and deported, despite providing the backbone of labor on sugarcane fields and at construction sites. And human rights groups say the government is stripping Haitian descendants who were born on Dominican soil of their citizenship, leaving a growing population of people that are effectively stateless.

Author Julia Alvarez, whose family fled the Trujillo dictatorship for the U.S. when she was a child, said the massacre stoked an anti-Haitian sentiment that remains a powerful force in Dominican society.

“The mentality that allowed the massacre to happen was there. Trujillo was tapping into something in the culture. He put gasoline on the fire,” said Alvarez, who has been part of the effort to organize the event. “It’s institutionalized now.”

Organizers hope the event will bring attention to the work of human rights groups in the Dominican Republic, many of which are working with Haitian immigrants and Dominicans of Haitian descent.

Father Regino Martinez, a Jesuit priest working on human rights cases in Dajabón, said the event would “break the silence” of the last 75 years.

He spoke as hundreds filed out of the Catholic church, lit candles and plodded toward the river a few blocks away.

Minutes after they arrived, the glow of candles appeared on the Haitian side of the river. A smaller group there commemorated the event with music and dancing before walking to the river, where they placed dozens of floating candles in the water.

On the Dominican side, a tearful Paulino watched from behind a fence that marks the border.

“Seventy-five years ago, people were throwing themselves in this river trying to escape the machete,” he said. “And today, the people … they’ve come to bear witness.”