Professor Ferrell was a student of American foreign policy and generally of American history. He came to Indiana University in 1953 and became a full professor in 1961. He taught at many institutions, the last being the United States Military Academy.
He published many books, including Woodrow Wilson and World War I, and America's Deadliest Battle: Meuse-Argonnne, 1918 (University Press of Kansas, 2007).