Book Review: Cedar Mountain to Antietam: A Civil War Campaign History of the Union XII Corps, July – September 1862


by M. Chris Bryan

El Dorado Hills, Ca.: Savas Beatie, 2022. Pp. xvi, 380. Illus., maps, appends., notes, biblio. $34.95. ISBN: 1611215773

The Union XII Corps in the Summer of '62

Bryan offers an account of the role of the Union's XII Army Corps during the summer of 1862. Formed earlier that year in the Shenandoah Valley from two veteran divisions, as the II Corps of Maj. Gen. John Pope's new "Army of Virginia", it was commanded by Maj. Gen. Nathaniel Banks.

On August 9th, an extremely hot day, the corps, numbering about 8,000, in the van of Pope's army, was covering Cedar Run, near Culpeper Court House. "Stonewall" Jackson approached with nearly twice the manpower, and prepared to attack. An artillery duel developed. Union gunnery proved very effective, disrupting his preparations. Smarting from earlier reverses at Jackson's hands Banks decided to attack first. Initially very successful – the Confederates briefly seemed to break – but Jackson counter-attacked, crushed the corps' right, and forced it to retreat. Banks had lost nearly a quarter of his troops, and many officers, dead, wounded, or missing, to Jackson's fewer than 10% casualties.

Sent to the rear, the corps missed the Union defeats at Second Bull Run and Chantilly (Aug. 28-Sept. 1). Some days later, with Lee invading Maryland, the corps was redesignated the XII Corps, given a new commander Maj. Gen. Joseph K. F. Mansfield, and ordered to join the Army of the Potomac.

At Antietam (Sept. 17th), the corps entered combat in the morning, tired and short of troops and officers. Mansfield was killed just as his men went into action. Nevertheless, they fought well in the muddled and gory combat at Dunker Church, some regiments exceeding fifty per cent casualties. After the battle, the new corps commander, Brig. Gen. Alpheus Williams, believed the courage and skill of his men were not properly acknowledged by McClellan.

Bryan takes a deep plunge into the life of the corps. Drawing heavily on unpublished manuscripts, and newspapers, as well as published works, he paints a detailed picture of its efforts, which are usual glossed over. His treatment flows well, is balanced, and easy to follow. His analysis of actions, often at the micro-tactical level, and descriptive narrative will be useful to scholars and armchair historians.

A good account, well written, Cedar Mountain to Antietam is highly recommended.


Our Reviewer: David Marshall has been a high school American history teacher in the Miami-Dade School district for more than three decades. A life-long Civil War enthusiast, David is president of the Miami Civil War Round Table Book Club. In addition to numerous reviews in Civil War News and other publications, he has given presentations to Civil War Round Tables on Joshua Chamberlain, Ulysses S. Grant, Abraham Lincoln, the Battle of Gettysburg, and the common soldier. His previous reviews here include Stephen A. Swails, The Great ‘What Ifs’ of the American Civil War Chained to History, Grant vs. Lee: Favorite Stories and Fresh Perspectives from the Historians at Emerging Civil War, Spectacle of Grief, Braxton Bragg: The Most Hated Man of the Confederacy, First Fallen: The Life of Colonel Ellsworth, Their Maryland, The Lion of Round Top, Rites of Retaliation, Animal Histories of the Civil War Era, Benjamin Franklin Butler, Dreams of Victory: General P. G. T. Beauregard, Bonds of War, Early Struggles for Vicksburg, True Blue, Civil War Witnesses and Their Books, Love and Duty, When Hell Came To Sharpsburg, Lost Causes, Six Miles From Charleston, Five Minutes to Hell, "If We Are Striking for Pennsylvania", and James Montgomery: Abolitionist Warrior



Note: Cedar Mountain to Antietam is also available in e-editions.


StrategyPage reviews are published in cooperation with The New York Military Affairs Symposium

Reviewer: David Marshall   

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