Signal Towers and Trees on the Petersburg and Bermuda Hundred Fronts: Stations of Observation and Communication
Although telegraphy was used extensively during the Petersburg campaign, signal trees, towers and buildings remained vital tools for each army to observe the movements of the enemy from an elevated vantage point. Information gained from such observations could then be relayed through all available means of communication, including signaling by flag or torch.
Military uses of these locations included artillery spotting, mapping, and photography. The fourth estate also climbed these posts as special artists drew the siege lines and battlefields and reported war news.
Fort Fisher Signal Complex
The Federal signal tower behind Fort Fisher on the western end of the Union lines at Petersburg is a good study of how signal stations were used in multiple ways.
The sketch below, done by topographic engineers, illustrates how Federal mappers used the signal tower and signal trees located on the parapets of Fort Welch and Fort Fisher to map the Confederate lines from a safe distance. The penciled lines represent lines of sight to various landmarks from the signal tower.
The signal tree on the parapet of Fort Fisher can be seen on the left in the drawing below.
The view was spectacular from the signal tower. The newspaper illustration below shows Fort Fisher, before the southern two bastions were constructed, and the U.S. and Confederate picket lines beyond, with the Confederate line and the city beyond that. Movement on the Boydton Plank Road and the South Side Railroad could also be observed from the tower.

Imagine hauling a Civil War era camera and glass negative(s) to the top of the signal tower! The result is the view below, looking to the northeast of the Union line, and capturing deserted camps, picket posts and Fort Conahey. It is not known who took this photograph,which seems to have been taken after the city fell and the armies moved west.
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Dec. 20th, 1864. "Hine is very friendly to me again, having got over his pet. He begins work today on a Signal Tower 140ft. high and 40 x 40 at the base. Builds of hewn timber secured with screw and bolts and braces. This is a very disagreeable task to be done at this season when cold winds are so frequent. From the top of this tower, which is to be placed upon an eminence near our camp, the Signal officer expects to overlook the whole Rebel left and all the roads leading out of Petersburg. By means of the tower, we shall be kept informed of all movements of troops on the part of the enemy." --William Watts Folwell Diary, 50th New York Engineers |

Other signal locations

“On the edge of the lines, not far from the headquarters of General Warren, stood a tall tree. It had been stripped of its boughs, and where the topmost limbs branched a crow’s nest of planks had been built for observatory purposes. The Confederate sharpshooters used this as a target. It was ninety feet from the ground, and its little telescope gave an admirable view of Petersburg and its defenses. The ascent was most uncertain. Rude cleats had been nailed on by a single spike, and these slipped and slanted most distressingly under the feet. In a moment of friskiness, soon regretted, I asked the signal officer in charge of this observatory if I might climb to the top and make a bird’s-eye sketch. He said I might if my courage held out. This was insulting, but turned out to be prophetic. He went up ahead and reached the top a dozen cleats ahead of me. He took one look, and then yelled: “Look out! They’re going to make a charge!” Sure enough they were. The rifles in the breastworks that protected the signal station began to crack. I craned my neck around the tree and saw a straggling lot of rebel skirmishers scampering across the fields toward the tree. Bullets whizzed by. The rickety cleats were gone in places, and others were so loose that they turned unless both feet met on them at once. The agony of that descent was indescribable. With the lieutenant treading on my fingers from above, the chance of being shot in midair or captured at the bottom of the ladder filled me with nervous terror. At last I sank exhausted into a rifle pit near the foot of the tree, completely unnerved. I was quite ill for three days as the result of this adventure. The Confederates were driven back. On the second day they renewed the attack and captured the tree. On the third day it was retaken. This struck me as useless trouble. They could have kept if for all I cared. I did not want it.”
--Joseph Becker, The American Magazine, vol. 37 (1894): 746-748. |

LC 22507. William Waud. View from Weitzels lookout & sig[nal] tower; Bermuda hundred looking south
Inscribed after title: shewing [sic] the Pontoon Bridge, Spring Hill Fort, the course of the Appomattox River & position of Gun Boats, Fort Clifton (rebel), Petersburg in the distance being shelled from out lines.
Inscribed above image from left to right: City Point; B- Point of Rocks landing; Point of Rocks; C The Chamberlain. Gen Graham's Flag Boat; D The Putnam; Woods on Fire; Broadway Landing; Woods on Fire; Troops moving; Dust - Troops moving; Spring Hill Fort; obstructions in the river made of piles of sunken boats &c to prevent the union boats ascending; The Clifton Rebel Battery; Troops moving; Petersburg, shelling along the lines; A - The Commodore Perry Gun Boat picketing the river.
Published in: Harper's Weekly, July 23, 1864, pp. 472-473.

LC 3c36820. A.R. Waud. In front of Petersburg. Inscribed upper left: enemies first line of earthworks our lines below and in front. Inscribed above image: Smoke of locomotive on Petersburg and Richmond RR. Inscribed lower left: This sketch was made at the request of Genl. Meade, for his use, from a tree used by the signal officers. It took over an hour and a half rebel sharpshooters kept up a fire at me the whole time. Inscribed upper right: Smou[ldering? ...]

Drawing of winter quarters of 9th New York Heavy Artillery at Petersburg- with signal tree in the background. Drawn by private Benjamin L. Avery. Thanks to Edward Alexander for sharing this drawing! The Ninth New York Heavy Artillery, a History of its Organization.... Alfred Seelye Roe, 1899: after page 216.