James Oliver Horton, professor of American Studies and history at George Washington University, will lecture on "Exploring the Racial Frontiers of Public History" on Wednesday, May 2, at the University of Å·ÃÀ¿Ú±¬ÊÓƵ at Boulder. Horton, who is also director of the Afro-American Communities Project of the National Museum of American History at the Smithsonian Institution, will address the efforts of historians to present America's racial past to the American public at historical sites.