There's been a quiet revolution in America's schools over recent decades. We've added a whole extra grade to a child's education: Preschool.
Economists love preschool. They say it's the smartest way to spend public money, especially in a tight economy. And they have lots of data to prove it: Preschool is perhaps the most researched idea in all of education.
This documentary takes us back to the 1960s to tell the story of a landmark experiment that helped launch the preschool movement. Fifty years later, researchers are still learning powerful lessons for today's youngest students.