In 1996, Groundswell’s first mural went up on a building in Williamsburg. That piece, addressing the topic of tenants’ rights, no longer exists. It’s been whitewashed. But the nonprofit, which is dedicated to student art and activism, is still making its mark across the city with 500 murals and counting.

Robyne Walker Murphy, the social justice organization’s new executive director, has noticed Groundswell’s work as long as she’s lived in New York, some 18 years now.

“These murals were just a part of the landscape — part of my daily walk or just being in the neighborhood,” said Murphy, an art and social justice educator and administrator who joined the organization a year ago. “You would just see them everywhere.”

The murals are a large part of the organization’s mission — working with teaching artists, students primarily from ages 16 to 19, local groups and schools to address issues affecting the community and creating public art that reflects those issues.

“We’re not just painting things to make it really beautiful,” Murphy said. “We’re speaking to issues like police brutality and sexual harassment. We’re also talking about possibility and celebrating the beauty in these communities, too.”

In recent years, Groundswell has also expanded its programming to reach more students and people interested in “artivism” — a portmanteau of art and activism.

At its Gowanus studio, free after-school offerings for high school students include its Teen Empowerment Mural Apprenticeship, where participants learn how to use art for social change; a portfolio program that helps students with the college admissions process; Voices Her’d, which works with young women to tell their stories; and Making His’tory, which is geared toward young men of color exploring issues of identity and injustice.

One of Groundswell’s newest programs is on Rikers Island, where it has partnered with the Department of Correction to create murals with young people incarcerated there. The group started its second yearlong residency there this month and expects to work with around 130 youths this year.

“We want to make sure that those young people that are there are not forgotten, and there is some outlet,” Murphy said.

Groundswell has a staff of about 30 teaching artists and often recruits new artists interested in youth development. To better prepare new staff, the organization just launched a new teaching artist training program so that its artists understand how to teach through a social justice lens — from finding what issues are relevant to young people to helping them understand and think critically about them.

“A lot of times in the education system, we’re talking about symptoms. What we need to talk about is the root — what is the institution that this is breeding from? How do we help young people understand these systems?” Murphy said. “That’s when they start to understand the world that they are in. We’re teaching young people to think critically about their art, think critically about their world.”

As Groundswell marks more than 20 years in the art and social justice space — they’re holding their annual art bash Monday at the Wythe Hotel in Williamsburg — Murphy is focusing on ways to reach more people, from increasing its college and career counseling for students to organizing public events and panels that address art, social justice and youth activism.

“We’ve been working really hard the last 20 years and building and building and building, and now we’re ready to continue to build and also go deeper and share what we’ve learned with the rest of our community,” Murphy said. “We have such a large footprint. We’re ready to push ourselves in the activism field and I hope develop the next generation of young artivists.”