- Joined
- Sep 2, 2019
- Location
- Raleigh, North Carolina
Some historians have written that, during the Civil War, commanders used a rule-of-thumb that an attacker needed at least a three-to-one numerical advantage to attack an entrenched defensive position.
Whether this is really a valid rule is interesting, but my real question is this: Can anyone point to a explicit Civil-War-era statement of this rule in any kind of source contemporary to the war?
I'm researching the use of fortifications during the war and am interested in the value of entrenchments as a deterrent. So what I would love to see is any quote from a Civil War commander, a military manual, a primary source of some kind, even a newspaper, expressly stating that a three-to-one rule (or any other ratio, I guess) was currently in use at the time.
One example of a historian citing this rule is James McPherson in Battle Cry of Freedom (1988). I found two places where he mentions the three-to-one rule:
"And while loose-order tactics occasionally succeeded in carrying enemy lines, they did not restore dominance to the tactical offensive, especially when defenders began digging trenches and throwing up breastworks at every position, as they did by 1863 and 1864. It became a rule of thumb that attacking forces must have a numerical superiority of at least three to one to succeed in carrying trenches defended by alert troops." (Chapter 15, "Billy Yank's Chickahominy Blues." Page 475 in my Kindle version.)
and:
"Ensconced behind the most formidable works of the war, the rebels had taken heart. They proved the theory that one soldier under cover was the equal of at least three in the open." (Chapter 21, "Long Remember: The Summer of '63." Page 632)
McPherson makes this claim. However, I'm not able to find a footnote or reference in his book pointing to any primary source that supports this rule-of-thumb.
Whether this rule is valid or not has been debated, but I'm just wondering whether this three-to-one ratio was really in use during the war, or whether it is a later invention.
Any thoughts?
(Image source: Henry T. Guion, Lt. Col. Eng. and Art'y, CSA. 1863 map of the entrenchments at Raleigh, NC. Detail at the southwest of the ring of fortifications.)
Roy B.
Whether this is really a valid rule is interesting, but my real question is this: Can anyone point to a explicit Civil-War-era statement of this rule in any kind of source contemporary to the war?
I'm researching the use of fortifications during the war and am interested in the value of entrenchments as a deterrent. So what I would love to see is any quote from a Civil War commander, a military manual, a primary source of some kind, even a newspaper, expressly stating that a three-to-one rule (or any other ratio, I guess) was currently in use at the time.
One example of a historian citing this rule is James McPherson in Battle Cry of Freedom (1988). I found two places where he mentions the three-to-one rule:
"And while loose-order tactics occasionally succeeded in carrying enemy lines, they did not restore dominance to the tactical offensive, especially when defenders began digging trenches and throwing up breastworks at every position, as they did by 1863 and 1864. It became a rule of thumb that attacking forces must have a numerical superiority of at least three to one to succeed in carrying trenches defended by alert troops." (Chapter 15, "Billy Yank's Chickahominy Blues." Page 475 in my Kindle version.)
and:
"Ensconced behind the most formidable works of the war, the rebels had taken heart. They proved the theory that one soldier under cover was the equal of at least three in the open." (Chapter 21, "Long Remember: The Summer of '63." Page 632)
McPherson makes this claim. However, I'm not able to find a footnote or reference in his book pointing to any primary source that supports this rule-of-thumb.
Whether this rule is valid or not has been debated, but I'm just wondering whether this three-to-one ratio was really in use during the war, or whether it is a later invention.
Any thoughts?
(Image source: Henry T. Guion, Lt. Col. Eng. and Art'y, CSA. 1863 map of the entrenchments at Raleigh, NC. Detail at the southwest of the ring of fortifications.)
Roy B.