My previous two posts dealt with the unsuccessful attempt by combined Federal forces to take control of the last two supply routes into Petersburg, the Boydton Plank Road and the South Side Railroad. Union troops outnumbered their Confederate opponents by a wide margin in nearly all of the battles during the siege, so why was it so difficult for them to be victorious and bring an end to the war?
Throughout the Civil War, the army that fought from behind prepared defenses usually defeated the attacking army, even if the attackers outnumbers the defenders. Some earthworks were hastily constructed, such as the Union position along Cemetery Ridge at Gettysburg. A low rock wall served as a base upon which the soldiers heaped earth dug out from behind the wall. This both added height to the protecting wall and provided them with a shallow trench in which to kneel.
But at Petersburg, the entrenchments were far stronger and much more complex. Mountains of earth were moved. Forests of trees were cut down and the timber added to the fortifications. Deep trenches protected the men from sharpshooters’ bullets and bombproof shelters provided protection from artillery shells. To give you a better understanding of the difficulty of taking a portion of these entrenchments by direct assault, the photos below show various features of the siege lines.
This photo is from Civil War Journeys. The line of earthworks in the background is certainly the main line. Notice the torn up railroad bed going across the middle of the photo. The pile of brush in front of the crude barricade in the foreground is called abatis. I could be wrong, but it appears the enemy would attack from the left, and this barricade position would be used if any forced their way into the railroad cut. Notice also the piles on things that look like barrels near the upper right.
This is another photo from Civil War Journeys. This is what we normally refer to as breastworks. An earthen trench with a log wall for protection. Earth was often piled against the outside of the works. Sometimes, the topmost log was raised a few inches so that the soldiers could fire their weapons through the gap.
This is a portion of the Union works known as Fort Sedgwick. The photo is from the U. S. Corps of Engineers Digital Library. Notice the use of pointed sticks (chevaux de frise). The works were also built with arcs and angles to funnel approaching enemies into areas of concentrated fire. Notice also the neat lines of those barrel-looking things along the top of the works in the background.
Those things that look like barrels are called gabions (yes, another French term.) They were widely used in the Petersburg works because gabions could be easily made from what they had on hand, lots of small tree branches. A great article on the construction and use of gabions can be found on the To the Sound of the Guns blog.
I hope you found this information helpful. As always, if you have any questions or comments, please submit them and I will happily answer.