“Halleck originates nothing, anticipates nothing, to assist others; takes no responsibility, plans nothing, suggests nothing, is good for nothing.” Lincoln’s secretary of the navy Gideon Welles’s harsh words constitute the stereotype into which Union General-in-Chief Henry Wager Halleck has been cast by most historians since Appomattox. In Halleck: Lincoln’s Chief of Staff, originally published in 1962, Stephen Ambrose challenges the standard interpretation of this controversial figure.

Ambrose argues persuasively that Halleck has been greatly underrated as a war theorist because of past writer’s failure to do justice to his close involvement with three movements basic to the development of the American military establishment: the Union high command’s application—and ultimate rejection—of the principles of Baron Henri Jomini; the growth of a national, professional army at the expense of the state militia; and the beginnings of a modern command system.