That our country could tear children away from their families is inconceivable to most Americans. And we are rising up.

Today, Americans are participating in rallies across the country to show support for the 2,500+ children separated from their families at the US/Mexico border, and to urge the government to reunite them now.

The outpouring of support for children separated from their families at the border is hugely heartening to my colleagues at the Lumos Foundation and me. Lumos has been promoting families as the best caregivers for children since J.K. Rowling established the organization in 2005, after she saw a photo of a child in an institution – in a cage – in the Czech Republic.

Lumos has worked with governments across Eastern Europe to dramatically reduce the number of children in institutions and move them back home to their families or, where that is not possible, to find them family-based care, such as foster or adoptive families. For the last few years, Lumos has turned its focus to this hemisphere, working in Haiti and more latterly in Colombia to get children out of institutions and back to their families.

The scale of the problem is staggering. Eight million children worldwide, at minimum, live in institutions – orphanages, detention centers, prisons, residential hospitals – without family care.

Of these eight million children, 80% have at least one living parent. More have kin or communities that would gladly take them in. Like the children taken from their parents at the US/Mexico border, most children living in institutions around the world have families that want them and could care for them.

What forces these kids from their families and drives them into institutions? One driver is violence and conflict, as we’ve seen at the US/Mexico border. Gang violence is rife across several countries of Central America and has resulted in the flood of asylum seekers arriving at the doorstep of the United States. Lumos has been working in Bulgaria and Ethiopia to ensure the best care for children who have fled to these countries from the Middle East and Eritrea, escaping conflict or human rights violations.

Another driver into institutions – the number one driver globally – is poverty. Parents don’t have enough money to care for their children. They can’t afford school fees or medicines or adequate food and rely on orphanages to provide those things instead. Disability is high on the list, too; parents feel they can’t care for children with disabilities and may be persuaded, by stigma or by the state, to turn over their children to a residential institution.

Lumos has demonstrated that these challenges can be overcome by building up community services and providing parents with a little support. We’ve also demonstrated that this approach costs the same or less than operating institutions.

Even in the best-run institutions, children suffer dramatic consequences. Without the love and attention of a parent or other single caregiver, a child is likely to have stunted mental and physical growth, attachment disorder, and life outcomes that lag far behind those of people raised in families.

In Washington, New York, Abilene, Tucson, Honolulu, and more than 600 other cities, we are saying today, loud and clear, that Families Belong Together.

That goes for the 2,500 children separated from their parents at the US/Mexico border – and for the eight million other children worldwide living without their families.