Christian M. DeJohn is a military historian, former sergeant in the US Cavalry, and Army veteran of overseas service in Bosnia, Egypt, Korea, and Germany. Called to active duty after the September 11 attacks, he served as a gunner and driver in an M1A1 Abrams tank with the 1/104th Cavalry, and as a dismounted cavalry scout patrolling rural Bosnia while a member of the historic First Troop Philadelphia City Cavalry, founded in 1774.

He has worked at the US Army Military History Institute, Carlisle Barracks, and the Department of Veterans Affairs. DeJohn's articles on military and American history have appeared in newspapers, magazines, books, and encyclopedias, such as the Washington Times, Philadelphia Inquirer, The American Legion Magazine, Main Line Magazine, and The Dictionary of American History. He holds a BA in political science from The American University, Washington, DC, and has completed all required credits towards a master of arts in military and American history.

"For Want of A Gun: The Sherman Tank Scandal of WWII" began as the heart of the  DeJohn vs. Temple free speech case, a historic First Amendment decision at the state and federal levels and victory for student campus free speech which struck down Temple University's illegal campus "speech codes."

The legal team which fought and won the DeJohn vs. Temple decision was led by David French, National Review writer, free speech attorney, Iraq War veteran, New York Times best-selling author, and proposed third-party Presidential candidate in the 2016 election.

DeJohn is a Life Member of the Veterans of Foreign Wars, the American Legion, the US Cavalry Association, and has been commissioned in the Honorable Order of Kentucky Colonels.  He also assists the Delaware County, Pennsylvania Veterans' Memorial, known for its statue of Sgt. "Wild Bill" Guarnere of "Band of Bothers" fame.