Mayors and community leaders across the country are working every day to create vibrant and healthy cities where all of our youth, families and neighbors can thrive. All too often, though, the promise of safe, healthy and hopeful communities for all is not being realized for African-American men. Indeed, while they represent significant populations in many of our cities, black men are disproportionately impacted by violence and other systemic barriers to opportunity.

The leading cause of death for African-American men age 10-24 is homicide. In fact, black males experience homicides at more than four times the rate of all other men in the United States.

Since 1980, more than 650,000 people have been murdered in the United States. That's more lost to homicide than Americans killed during all the wars of the last 100 years combined. In New Orleans, like in other cities throughout our country, African-American men continue to suffer disproportionately: About 6,000 black males have been killed in New Orleans since 1980 -- more than 90 percent of the city's murder victims over that period.

Statistics like those are unacceptable. African-American men are assets to our families, communities and cities. That's why we must address an urgent issue for the prosperity of cities and our nation: stemming the tide of violence against and among African-American men. And for our cities to prosper, we have to do all we can to create opportunities for our boys and young men to live their lives to the fullest potential.

Five years ago, a group of mayors partnered with philanthropic and community leaders to form a network of local communities focused on eliminating violence in American cities related to African-American men. Today, nearly 80 mayors across the country are part of Cities United, working together as a national movement to uplift black men while confronting the urgent crisis they face.

Through Cities United, we address the root causes of violence against African-American men and help to build pathways to justice, employment, education and increased opportunity. In New Orleans, we're working to build a city where law enforcement and citizens see each other as partners and all residents feel safe. We do this by proactively engaging community members, clergy and business leaders in ongoing meetings aimed at increasing trust and transparency.

Earlier this month, Cities United brought together cities around the country to Birmingham, Ala., to accelerate our momentum. The gathering focused on addressing trauma in communities impacted by violence, creating more employment opportunities and job training, reforming the criminal-justice system and uplifting the voices, leadership and perspectives of youth. This year's theme, "The Fierce Urgency of Now," was selected because we know that our work is far from done. It is more important now than ever.

That is why we call on mayors and other city leaders to join us in this movement. There are numerous things leaders can do. We can work together to develop a proactive and reactive strategy across government agencies, the public and private sectors, age groups, civic and community organizations, and faith institutions. This means committed leadership across the board, from mayors and police chiefs to education and health leaders as well as neighborhood leaders and youth. This effort must transcend local election cycles.

To bring local efforts to scale, city leaders and community members can get involved with the Cities United network to identify and share the most effective solutions to reducing violence against our African-American boys and men, so we can make our cities more livable.

We know that reducing the impact of violence on African-American men strengthens communities, cities and the nation. The Centers for Disease Control and Prevention estimates, for example, that reducing violence by 50 percent would save more than $35 billion in annual medical and lost productivity costs.

By working together, we can restore hope to families and communities devastated by violence and achieve our vision of vibrant and healthy cities.