... Rep. Elijah Cummings offered an impassioned ode to children at this month’s congressional hearing on Flint. “I’ve often said that our children are the living messages we send to a future we will never see,” the Maryland Democrat said. “The question is: What will they leave us? And how will we send them into that future? Will we send them strong? Will we send them hopeful? Will we rob them of their destiny? Will we rob them of their dreams? No, we will not do that!”

This is a fairly modern way of thinking about children — as vulnerable beings we should cultivate and protect. Of course, the impulse to protect children may have an evolutionary dimension. Individual parents may be genetically programmed to invest in the survival of their offspring. But the notion that children are innocent, fragile creatures that society as a whole should shelter from contamination is a relatively recent idea.

In my research, I’ve documented how colonial Americans considered children depraved. Babies, they thought, were dangerously unformed, immoral and animalistic, as evidenced by their inability to speak or stand. Parents were expected to teach their children to walk upright, help them to memorize scripture and then put them to work as soon as possible. By contemporary standards, there was a surprising lack of concern for children’s welfare. Children frequently suffered severe burns playing near fireplaces, fell into uncovered wells or were attacked by wild animals, all suggesting an absence of adult supervision. Yes, many children died of diseases not then treatable. But they also died of easily preventable causes.

Around the middle of the 18th century, attitudes began to shift. Drawing on John Locke’s notion that children are blank slates and Jean-Jacques Rousseau’s concept of children as pure and spontaneous, a romantic vision of childhood encouraged parents to shelter their children from adult realities to preserve their innocence. Parents kept children at home, in school and away from work longer than in the past. And an array of new institutions — from public schools to orphanages to children’s hospitals — emerged to protect children’s welfare.

Still, the overwhelming majority of 19th-century American autobiographies report children being disciplined with a cane, paddle or leather strap. Child abuse and neglect became criminal offenses starting only in the 1870s. Mandatory schooling did not become universal until the early 20th century. The United States abolished child labor only in 1938.

Slowly, incrementally, protecting children from harm became a public priority. Indeed, the growth of the American welfare state, from Aid to Dependent Children in the 1930s to Head Start, established in 1965, was largely driven by concern for children’s well-being. This effort to ensure a “right to childhood,” free from abuse or exploitation, was bipartisan and reflected a growing consensus that children, by virtue of their special vulnerability and their role as our collective future, deserve public support. ...