On March 16, 1968, Dr. Martin Luther King, Jr. made his last visit to the city of Los Angeles. He used that occasion to deliver a speech calling for an end to poverty, and to build support for a Poor People's Campaign to demand jobs, health care and housing for the country's poor.

Reflecting on the moment he said, “We are faced with a situation where we find restlessness among the poor, and discontent among the affluent…Our nation is in a mess. The world is in a mess. Now the question is: what do we do?”

Forty-four years later the relevance of these words is striking. There's no doubt that all of us – families seeking employment, veterans returning from war, and nonprofits and government agencies seeking to serve them – are feeling the strain of tough times. Yet, as many are asking “what do we do?,” so many more are answering that question as Dr. King did, using service and volunteering to tackle local challenges and strengthen their own and each other's economic security.

Dr. King believed that service is central to meeting the challenges of poverty, joblessness and social divides, and empowering ourselves at the same time. As we celebrate the King Holiday on Monday, Dr. King's vision for service and volunteering is alive in Los Angeles and across California where citizens, businesses and schools are embracing service as a powerful way to advance King's dream of opportunity for all.

The Corporation for National and Community Service, the federal agency that engages more than four million Americans in service, working with the King Center, leads the effort to make the MLK Holiday “a day on, not a day off.” This year, Americans from every state will fulfill that promise by providing job training and mentoring to unemployed workers, refurbishing schools and community centers, collecting food and clothing, signing up mentors, supporting veterans and military families, promoting nonviolence, and more, with many projects starting on King Day and lasting throughout the year. And as is so often the case, Los Angeles is leading the way.

As a City of Service, Los Angeles has developed and implemented a citywide plan to increase volunteering and to engage the members of the community in meeting the city's greatest needs. Since launching the We Serve L.A. Initiative two years ago, thousands have answered the challenge to volunteer in critical areas including education, economic development and the environment. And our city's commitment to service continues to grow. Last year, approximately 62.8 million Americans volunteered in some way in their communities. California's reported 7 million volunteers include 2.1 million Angelenos who provided service valued at more than $6.2 billion last year.

Los Angeles has long partnered with the Corporation for National and Community Service and its AmeriCorps and Senior Corps programs to place hundreds of teachers, tutors, and mentors into the least resourced schools, and provide job skills and financial training to help Angelenos advance their career opportunities.

This year alone, Los Angeles city leveraged more than $12 million in funding from CNCS and more than 900 AmeriCorps members who engaged more than 4,000 volunteers. These volunteers are advancing economic opportunity by building their own and others' skills, preparing our students for success, and creating new entryways to the workforce.

For example, AmeriCorps members working with the Building Skills Partnership have made a significant impact for janitors, service workers and their families in downtown Los Angeles. By training additional volunteers, enrolling workers in ESL classes and computer classes, and making them aware of college scholarships other services, they are making it possible for service workers to advance in the workplace and send their children to college.

AmeriCorps members serving with the California Energy Service Corps are increasing the energy and water efficiency of low-income homes in Los Angeles, saving residents money while they build the skills necessary to obtain “green” jobs. Similarly, as part of the Wildlands Recovery Team, AmeriCorps members are conducting disaster preparedness and environmental preservation projects, while creating pathways to work with the National Parks Service and disaster response teams.

In South Los Angeles, youth prone to gang violence and severe academic challenges are succeeding in school thanks to AmeriCorps members who are providing one-on-one tutoring and mentoring with Reach Me, Teach Me. By addressing education inequities in our communities, these individuals and other AmeriCorps members serving with programs including Jumpstart and Teach for America are creating pathways to economic opportunity by equipping students with the life, academic and workforce skills they need to go to college, be self-sufficient and attain family-sustaining careers.

These are just a few examples of high impact national service projects happening across the state. We are fortunate that in California, Governor Jerry Brown and former Governor Arnold Schwarzenegger are equally committed to national service as a way to engage citizens and build the capacity of organizations and communities to solve problems.

In fact, California led the way in advancing service as a solution by appointing the first-in-the-nation state cabinet Secretary of Service and Volunteering. Similarly, Mayors and Presidents of both parties have understood the value of national service. Advancing opportunity through service is exactly the kind of common ground that we need right now.

After his final visit to Los Angeles, Dr. King joined sanitation workers protesting for fair wages and better work conditions in Memphis, Tenn. While there he delivered one of his most memorable speeches, “I've been to the Mountaintop.” Thinking about Dr. King's final days, it's easy to wonder what he would see if he stood on that same mountaintop today. If he looked to the left, he might see our country's great need to improve education and our efforts to make sure every student has the support he or she needs to succeed. If he looked to the right, he might see the struggle with unemployment and housing.

But if he looked forward at the city of Los Angeles and at other Cities of Service, he would see countless citizens united by their desire to change this reality, and determined to make that change happen through their own ideas and actions. Service is our response to the question “what do we do?” that Dr. King posed to the citizens of Los Angeles and the nation so many years ago.

Dr. King devoted his life to advancing equality, social justice, and economic opportunity for all. He challenged us to build a more perfect union and taught us that everyone has a role to play. Four decades later, we still have work to do to realize Dr. King's dream. The needs are great, many Americans are hurting, and government can't do it alone.

On this MLK Day of Service, we encourage all U.S. mayors to realize the full potential of citizen service by joining Los Angeles as a City of Service. And we'd ask every one of us to look around, take in the view and ask ourselves: what do we see from the mountaintop, and how are we willing to serve each other and our communities to change it.

Antonio R. Villaraigosa is the Mayor of Los Angeles and the President of the United States Conference of Mayors.

John Gomperts is the Director of AmeriCorps at the Corporation for National and Community Service, the federal agency that engages more than 4 million Americans in service through Senior Corps, AmeriCorps, and Learn and Serve America, and leads President Obama's national call to service initiative, United We Serve.