This month marks the 20th anniversary of the genocide in Rwanda, which left 1 million people dead and many more raped, injured, and traumatized. As we look back, there's much discussion about the country’s remarkable reconciliation and reconstruction efforts, the women who comprise a world-record 64 percent of the Rwandan legislature, and the country's efforts to position itself as the technology leader in the region. But there is something else Rwanda is doing that we should be talking about: mandatory, nation-wide community service, or Umuganda, which translates from Kinyarwanda as “coming together in common purpose.”

The government leaned on this tradition to help heal and rebuild the country; while the precolonial tradition was voluntary, it became mandatory in Rwanda. For a time, the government required that people work three days per week. People from previously warring tribes worked together to build roads, bridges, schools, health centers, government and cooperative buildings, and housing. They also planted trees and crops, and cleaned and groomed public spaces.

However effective, the government imposes Umuganda, charging fines for noncompliance (which some might call draconian), and the practice has a checkered history. Prior to colonization, the Hutu, Tutsi, and minority Twa groups all practiced Umuganda.

But the Germans and later Belgians coopted Umuganda during colonization. Rather than a community-led support system, it amounted to forced, unpaid collective labor. Even when Rwanda won its independence in 1962, the newly formed government relied on Umuganda for farm labor and to promote the government’s political agenda. Though both periods saw vast infrastructural improvements, Umuganda was more bootcamp than barn raising. During the genocide, those in power twisted Umuganda into a most perverse form—for the purpose of killing and raping.

Last January I traveled to Rwanda with a delegation from Same Sky, a company that trains and employs HIV-positive women in glass jewelry making. The artisans make a higher-than-average wage, and Same Sky reinvests 100 percent of the net proceeds into training and employing more artisans.

Arriving in the capital city of Kigali, I discovered a bustling metropolis with solid infrastructure, ongoing construction, and people moving about freely. But what stood out most was how clean the city was. There was no litter; there were no plastic bags (now outlawed) or bottles by the sides of the roads. All of the grass and shrubbery was neatly pruned, and meticulously kept flower gardens dotted the landscape.

Kigali is one of cleanest cities I have ever visited. My hotel referred to Rwanda as “the Switzerland of Africa,” and modern-day, mandatory Umuganda has helped to achieve this reputation.

Our small delegation met with local artisans and business owners, students and professors, heads of government and nonprofit organizations, tour guides, drivers, and street vendors. Intrigued by Umuganda, I spoke with nearly everyone I met about it. One young woman told me that once during Umuganda, she and her friends were on their way to a wedding. A police officer stopped them and told them to participate. They were annoyed at first—they wanted to get to the wedding early and have time to visit before the ceremony. But they ended up enjoying themselves: They made new friends as they cleaned out a future garden area for a school. They had fun (and still made the ceremony).

I heard many other stories, and though some of the people I met said they resent that service is mandatory and state-centralized, most seemed very proud of the tradition.

Today, Umuganda happens for just three hours in the morning on the last Saturday of every month, but the results remain impressive: From July 2011 to June 2012, an estimated 80 percent of the population of 11.5 million participated in Umuganda, which equates to more than $18 million dollars in human services.

Some people complain that work such as grooming flower beds and cleaning up trash is too menial and boring, and despite all that it has accomplished, Umaganda retains an element of coercion—nobody likes being told what to do, and fining poorer Rwandans seems harsh.

But to me, there is beauty in this tradition, and it made me wonder whether we could export the concept of Umuganda throughout the world. The United States, for example, has its own strong history of community service: community clean-up days, Adopt-a-Highway programs, and numerous ongoing volunteer efforts. But just think what we could create if, say, the government facilitated a national holiday of sorts for service, where communities throughout the country planned volunteer activities to enhance their own towns and cities. Leaders across sectors could meet to determine how to organize and connect needed services with volunteers, drawing from Umuganda and other successful models such as the HandsOn Network, which brings together businesses, corporations, and foundations to support costs while coordinating community-wide efforts to promote volunteerism.

In a world where we tend to separate—whether on religious, socio-economic, or political grounds—finding new ways to “come together with common purpose” seems more important than ever, and Umuganda may just be a model we can build on.