Kate Clifford Larson, PhD., is an historian and author of "The Assassin's Accomplice: Mary Surratt and the Plot to Kill Abraham Lincoln" (Basic Books, June 2008). With degrees from Simmons College and Northeastern University, and a doctorate in history from the University of New Hampshire, Larson specializes in 19th and 20th century U.S. Women's and African American History.

Dr. Larson is also a leading Harriet Tubman scholar and the author of "Bound For the Promised Land: Harriet Tubman, Portrait of an American Hero" (Ballantine/One World, 2004), one of the first non-juvenile Tubman biographies published in six decades. She has been working as a consultant and interpretive specialist for numerous museum, community, and public history initiatives related to Harriet Tubman and the Underground Railroad in Maryland and New York, and also served as the consulting historian for the National Park Service's Harriet Tubman Special Resource Study, resulting in the introduction of the Harriet Tubman National Historical Park Act, now awaiting approval in Congress.

Dr. Larson has been a guest instructor at numerous professional development workshops for teachers, including National Endowment for the Humanities and Teaching American History programs, on the topics of American Slavery, the Underground Railroad, Abolition, and Harriet Tubman. She teaches at both Simmons College and Wheelock College in Boston. Her latest book, "Rosemary: An Interrupted Life," a biography of the profoundly disabled sister of President Kennedy, is due out from Houghton Mifflin Harcourt in late 2011.