Research and Teaching Interests: Immigration history, oral history, public history, and the history of the American West. Book: Imaginary Lines: Border Enforcement and the Origins of Undocumented Immigration, 1882-1930 (University of Texas Press, 2009). Finalist, William P. Clements Prize for the Best Non-Fiction Book on Southwestern America (2009). Professional Associations: Organization of American Historians, Western History Association, Oral History Association, Southwest Book Award, Border Regional Library Association (2010).