Last week, more than six hundred voices echoed across the gymnasium of St. Augustine High School in New Orleans, Louisiana. They belonged to students gathered to recite a pledge, but not the familiar ode to the stars and stripes. This one was a pledge against gun violence.

“I will never bring a gun to school. I will never use a gun to settle a personal problem or dispute,” the students said. “I will use my influence with friends to keep them from using guns to settle disputes.”

St. Augustine is a historically black all-boys Catholic School for grades six through twelve. Earlier that day in their classrooms, the young men signed sheets of paper printed with the same credo. At other schools in and around New Orleans, which has experienced more than 130 gun homicides in 2015, elementary grade students signed a simpler version, promising to not handle guns, and to alert an adult if they encounter one. In all, in November, nearly 21,000 children at more than 64 schools across Southeast Louisiana added their names to the Student Pledge Against Gun Violence.

The pledge itself is nearly 20 years old, and at its peak popularity reached upwards of four million students across the United States, according to its creator Mary Lewis Grow. She drafted the pledge in the mid-’90s in the wake of the country’s surging gun deaths, particularly among young people. As a longtime anti-violence activist, she noticed that children were not part of the conversation.

“Every time there’s a school shooting, all the talking heads are adults,” Grow says. “Nobody thinks of bringing young people themselves to the table.”

In 1996, after writing the first version of the pledge, Grow took it to school administrators in Minneapolis, near her home in Northfield, Minnesota. The reaction was positive, but she wanted a farther reach. The same year, she helped craft a Senate resolution calling for a National Day of Concern about young people and gun violence, along with national distribution of the pledge. Both Democrat and Republican senators got behind it as co-sponsors, including New Jersey’s Bill Bradley and North Carolina’s Jesse Helms. Grow also asked the famed designer Milton Glaser to donate a logo for the campaign: two hands raised in oath, which form a peace dove when turned sideways.

I will never bring a gun to school.

I will never use a gun to settle a personal problem or dispute.

I will use my influence with friends to keep them from using guns to settle disputes.

My individual choices and actions, when multiplied by those of young people throughout the country, will make a difference.

Together, by honoring this pledge, we can reverse the violence and grow up in safety.

“The Student Pledge Against Gun Violence”

For about a decade, spurred by federal support, the pledge took off. Easy, free, and non-political, it appealed to administrators in public and private schools all over the country, in cities like Chicago, New York, Washington, Birmingham, and New Orleans.

Over the years, Grow made only a few modifications to the pledge. One year, a father who’d lost a son in a fatal school shooting asked whether the pledge could be revised to encompass suicide. Moved by the thought, she changed the wording of the second line to incorporate the phrase “personal problem.”

But in 2007, when Grow’s husband was diagnosed with cancer, she lost her verve for spreading the word. She left the pledge to its own devices. Though it continued to be recited in some schools, the pledge fell into a lull along with Grow’s activism.

Then, after the Sandy Hook massacre in 2012, Grow started getting calls. Discouraged by the deadlock in Congress, people wanted to know about the pledge, whether the program was still alive. “I think they started looking for other ways to address gun violence,” Grow says. The inquiries rekindled her energy for the cause. In the past couple of years, the pledge has reappearing in schools in Louisiana, Mississippi, South Carolina, New Mexico, and Iowa.

“It is an opportunity to have this moment of reflection with young people about violence, and ask them, ‘What do you really want to see happening in your community?’” says U.S. Attorney Kenneth Polite Jr. of Eastern Louisiana. His district was one of the first to revive the pledge last year.

Underpinning the pledge is a belief that young people have the power to choose their own destiny — in this case, to decide whether or not to use a gun. Given the many strong forces shaping such decisions, how much difference could such a commitment actually make?

Research on pledges in other contexts has shown mixed results. One study, conducted in Scotland, found that a “no violence” pledge, among other interventions, led gang-involved youths to carry weapons at a lower rate while having negligible impact on their overall rate of physical violence. Pledges are “unlikely to actually have a major result, especially when you consider that there are other huge predictors of highly aggressive violent behavior,” says psychologist Dennis Embry, a senior scientist at PAXIS Institute in Tucson, Arizona. He stresses that pledges are just one piece of the puzzle; to be successful, they must be reinforced with other proven violence prevention techniques.

In 1996, Embry launched one of the earliest youth violence prevention studies in the U.S. His program, called PeaceBuilders, includes a pledge of its own. In it, students promise to “praise people, give up put-downs, seek wise people as advisors and friends, notice and speak up about hurts, right wrongs, and offer help.” Every bit of that language, right down to the verb tenses, is packed with underlying science on youth behavior. For example, the line about “giving up put-downs” is based on research that shows how insults act as a violence trigger.

Mary Lewis Grow never intended the Student Pledge Against Gun Violence to be a “bulletproof shield.” She hoped instead that it would merely open a door. That was true for Malik Gibson, a 17-year-old St. Augustine senior who lost one of his classmates to gun violence last summer.

“For me, it’s all about who you surround yourself with and what you do with your time that dictates if you are more likely to get involved or have an encounter with gun violence,” he says. “I keep myself busy. I get involved in clubs, activities after school, church, and in the community.”

“It won’t work for everybody,” he adds. “It’s harder for some people…because all they know is the negative.” But for students like Gibson, the pledge can serve as a necessary jolt. “Being that we are an all-black male school, a lot of these young men need that reassurance, that reminder, how guns impact our lives,” he says. “It’s a necessity.”