They Should Have Been Hanged is a collection of essays presenting a stimulating revisionist view of the U.S. Civil War. Gary Brecher aka John Dolan rejects both the Lost Cause myth and insipid mainstream histories. Instead, he relies on the testimony of contemporary figures like Mary Chesnut, Mark Twain, John A. Logan, and Adam Gurowski to show the American Civil War had its share of treachery, criminality, and error.

Referring to primary sources (letters, diaries, speeches) and secondary texts (biographies and histories), Dolan argues that McClellan was not just incompetent but sympathetic to the Confederate cause; that Gurowski long anticipated the necessity of hard war; that Congressmen were plotting treason long before 1864; and that the Burning of Atlanta was relatively mild in the context of 19th-century warfare.

Dolan pushes back against a modern right-wing contention that the Civil War was not about race or slavery and decries monuments like the one dedicated to Henry Wirz, who ran the Andersonville camp. Finally, he suggests that the tragedy of Reconstruction could have been avoided had certain Confederate figures faced justice in a timely fashion.