Chris Valdes on Good Morning America for the finale of "United States of Tacos"

Journalist and biographer Andrew Morton on the new Princess Diana documentary; United States of Tacos series concludes with the four finalists, judged by chef Chris Valdes, Mexican singer-songwriter and member of RBD Christian Chávez and New York Yankees Hall of Fame legend CC Sabathia; "GMA" Summer Concert Series continues with a chat and performance by Sam Hunt