Being a youth in America today looks very different from what we saw at the end of the 20th century. Increases in anxiety and depression, chronic diseases, the autism spectrum, developmental delays: American youth are facing many, daunting obstacles at dismayingly early ages. How and why have these rates increased over the past handful of years? What cross-sector collaboration is needed to improve the health of US children and adolescents? How can we identify and break down the barriers schools face in offering health education and infrastructure to build healthy habits? How can we join forces—families, educators, physicians, as well as young Americans themselves—to improve the physical and mental health of the next generation so that they will enjoy healthy, fulfilling lives?