Teaches U.S. History Formative and Modern periods, History of Civilization I & II,  Sectional Conflict and Civil War, Reconstruction and Later South, Progressive US: 1896-1920, History of Ohio, World War II, and Colloquium: Victorian England.

Ph.D. in history from Kent State University in 2006. The dissertation, Constructing Memories on the "River of Death:" Conflict, Landscape, and the Impact of the Spanish-American War on the Chickamauga and Chattanooga National Military Park received the Ohio Academy of History's Best Dissertation Award in 2007. It is currently being revised as a full length monograph entitled Conflicting Memories on the "River of Death": The Chickamauga Battlefield and the Spanish-American War  for the Kent State University Press, with a tentative publication date of 2011.

Earned an M.A. in History from Kent State University in 1984 and a B.A. in History from Kent State University in 1980

Has been tenure-track at the Ashtabula Campus since January 2007 and previously  worked as an adjunct at the Kent Campus, the Kent Stark Campus  and Tuscarawas Campuses, and Edison State Community College.

Professor Keefer is a member of the Ohio Academy of History, Southern Historical Association, Organization of American Historians, Society of Civil War Historians, Pioneer America Society, Society of Military History, American Historical Association, East Tennessee Historical Society, Museum of the Confederacy, and the Civil War Preservation Trust. He is an active Civil War and colonial period living historian and participates in annual events at Colonial Williamsburg,  the Gettysburg National Military Park, and the Antietam National Battlefield.