Watch VoirFilms. With one in eight American children suffering a confirmed case of neglect or abuse by age 18, there are currently more than 400,000 children in foster care in the U.S., a number that continues to grow each year. Drawing on unprecedented access, FOSTER explores the often-misunderstood world of foster care through compelling stories from the Los Angeles County Department of Children and Family Services, the largest county child welfare agency in the country.