He has been appointed a University Scholar in recognition of excellence in his research, scholarship, and teaching. Fennell has conducted archaeological investigations at 19th century sites in Illinois, Virginia, and South Carolina with grant support by the National Science Foundation and National Endowment for the Humanities. After clerking for the Honorable Jane R. Roth (D. Del./3d Circuit), he was a practicing attorney for several years in Washington, D.C., in the areas of antitrust, contracts, product liability, torts, false claims, and securities disputes.