Teacher Silvia Castillo, center, reads a book about dinosaurs with Everett Fisher, left, and Jaz Endicott in a toddler classroom at Kids First on Jan. 30, 2019, in Lincoln, Neb.
Jennifer Mojica, a Teach For America instructor, works with students in her math class at Holmes Elementary School in Miami on Sept. 1, 2011. The program helps staff low-income schools with young teachers, but it has shrunk along with the general teacher pipeline.