James, a leading interpreter of antebellum African American community life, was one of the discipline’s most influential public historians. He taught at The George Washington University in Washington, D.C. for more than 30 years where he was named the Benjamin Banneker Professor of History and American Studies and directed the George Washington University Center for Public History and Public Culture. He had a passion for teaching young minds and mentoring the next generation of scholars, and was nationally recognized for excellence in teaching. He was a Senior Fulbright Professor at the University of Munich in Germany in 1988 and 1989, held the John Adams Distinguished Fulbright Chair at the University of Leiden in the Netherlands in 2003, and served as a visiting scholar at the University of Hawai’i from 2006 through 2009. He lectured throughout the United States and Europe, in Thailand and Japan, and in 1991 he assisted the German government in developing American Studies programs in the former East Germany. James was the prototype of the American historian who perhaps more than anyone else helped to build the bridge between scholarship and public history, especially in the crucial fields of slavery, the Civil War era, and race relations. In 1981 he initiated the creation of the Afro-American Communities Project at the Smithsonian Institution’s National Museum of American History where for two decades he mentored scores of young historians, pioneered the study of nineteenth-century black communities, blending archival work with public history, deepened the relationship between African American studies and the Smithsonian, and assisted in the establishment of the Smithsonian Institute’s National Museum of African American History and Culture. In 1993 James was appointed by then Secretary of the Interior Bruce Babbitt to serve on the National Park System Advisory Board and in 1996 he was elected board chair. In 1994 and 1995 he served as Senior Advisor on Historical Interpretation and Public Education for the Director of the National Park Service (NPS), helping guide how the agency portrays the history of our peoples, and he subsequently conducted annual summer workshops for National Park Service park rangers. During 2004 and 2005 James served as the president of the Organization of American Historians (OAH), who later established the Stanton-Horton Award for Excellence in NPS History, where he helped to establish a close working relationship between the NPS and the OAH, and assembled a delegation of historians who helped to forge the publication of Humanities and the National Parks: Adapting to Change (1994). James also made forays into educational television, documentary film projects, and international education, serving as historical consultant to numerous film and video productions on ABC, PBS, the Discovery Channel, C-Span TV, and the History Channel. He appeared in many documentary films, became cohost of “The History Center,” a weekly program on The History Channel and was the subject of an episode in the series "Great Minds in American History" hosted by Roger Mudd. From 1998 through 2000 James served on the White House Millennium Council, together he and Lois accompanied First Lady Hillary Rodham Clinton on her "Save American Treasures" national tour of historic places, and in the fall of 2000, James was one of two historians appointed by President William Clinton to serve on the Abraham Lincoln Bicentennial Commission.

“History matters. It provides our national and personal identity. It structures our relationships, and it defines the terms of our debates… We can and must learn from it even if doing so is painful.”

- James O. Horton, 2006