For a lot of students, school is back in session. But for those in early childhood education, the path isn't very clear. Last year, America's public schools lost more than one million students who had been expected to enroll but didn't show up. Most of them were younger and living in low-income neighborhoods. The biggest loss was seen in the country's kindergarten classes. We talk about the little ones who got left behind and how to get them back on track in the first installment of our Back to School series.Want to support 1A? Give to your local public radio station and subscribe to this podcast. Have questions? Find us on Twitter @1A.