Allen is an author, educator, and historian. He has written six books: The Analyst; Teacher of Civil War Generals; Your Affectionate Father, Charles F. Smith; Charles A. Marvin - "One Year. Six Months, and Eleven Days", Preparing for Disunion, and Ebenezer Allen - Statesman, Entrepreneur, and Spy. He taught classes on the American Civil War at Collin College. He has visited more than 130 Civil War sites and given presentations at Civil War Roundtables.