Hillary Clinton is the first woman in US history to become the presidential nominee of a major political party, in 2016. She served as the sixty-seventh secretary of state–from January 21, 2009, until February 1, 2013–after nearly four decades in public service advocating on behalf of children and families as an attorney, first lady and senator. She is the author of It Takes a Village, What Happened, Hard Choices and Living History. She is a wife, mother and grandmother, and she lives in Chappaqua, New York. You can follow Hillary Clinton on Twitter @HillaryClinton or on Facebook at facebook.com/hillaryclinton.Chelsea Clinton is the author of Don’t Let Them Disappear: 12 Endangered Species Across the Globe; Start Now! You Can Make a Difference; She Persisted: 13 American Women Who Changed the World; She Persisted Around the World: 13 Women Who Changed History; It’s Your World: Get Informed, Get Inspired & Get Going! and, with Devi Sridhar, Governing Global Health: Who Runs the World and Why? She is also the Vice Chair of the Clinton Foundation, where she works on many initiatives, including those that help to empower the next generation of leaders. She lives in New York City with her husband, Marc, their children and their dog, Soren. You can follow Chelsea Clinton on Twitter @ChelseaClinton or on Facebook at facebook.com/chelseaclinton.