Book excerpt: Who are we, and where do we come from? The fundamental drive to answer these questions is at the heart of Finding Your Roots, the companion book to the hit PBS documentary series. As scholar Henry Louis Gates Jr. clearly demonstrates, the tools of cutting-edge genomics and deep genealogical research now allow us to learn more about our roots and look further back in time than ever before. In the second season, Gates's investigation takes on the personal and genealogical histories of more than twenty luminaries, including Ken Burns, Stephen King, Derek Jeter, Governor Deval Patrick, Valerie Jarrett, and Sally Field. As Gates interlaces these moving stories of immigration, assimilation, strife, and success, he provides practical information for amateur genealogists just beginning archival research on their own families' roots and details the advances in genetic research now available to the public. The result is an illuminating exploration of who we are, how we lost track of our roots, and how we can find them again.