Dimmock Line, The


The Dimmock Line was a series of fifty-five artillery batteries and connected infantry earthworks that were constructed between 1862 and 1864 in a ten-mile arc around Petersburg during the American Civil War (1861–1865). The earthen fortifications were built using Confederate soldiers and enslaved laborers and covered lands east, south, and west of Petersburg. They were constructed to protect the city’s industry and railroads in the event that Petersburg was attacked. Union troops finally attacked Petersburg directly and elements of the Dimmock Line fell to them in mid-June 1864, which began the Petersburg Campaign.

Building the Dimmock Line

Early in the spring of 1862, Petersburg’s Common Council created a committee to investigate the need for defenses to be constructed around the city. Little came of this measure, however. Work on a defense line began that summer when Major General Daniel H. Hill used troops from North Carolina, Virginia, and Georgia to construct the initial defenses. General Robert E. Lee dispatched engineers to Petersburg to design a line of defense for the city by early August. Much of the responsibility was passed off to Captain Charles Dimmock. Under Hill’s orders, Dimmock used soldiers and enslaved laborers to perform the work. The men worked early in the morning and late in the day to build the fortifications. Some 264 slaves from Virginia’s Eastern Shore and more than 1,000 from North Carolina turned over the soil. Confederate troops dispersed late in August, however, as did many of the enslaved laborers. Major General Samuel French requested 150 additional slaves to work on digging the Dimmock Line early in September.

Though Dimmock kept several hundred enslaved laborers at work, shortages of manpower delayed the construction of the fortifications. The General Assembly passed a measure that stated that slaves could be impressed to construct earthworks, though members bowed to planter unrest by creating county quotas and limiting the number of slaves to be conscripted from any individual owner. In addition to this, no slave was to work longer than sixty days in this capacity. By December 1862, Dimmock told the Petersburg Common Council that the defenses were still not finished and he requested “200 negroes” to perform the labor. The slaves were “to report each morning upon the work … at eight o’clock [and] to be dismissed and permitted to return home at 4 p.m.,” which he saw as a means to preserve the slaves’ health from “nefarious discomfort and exposure of camp life.”

Labor on the Dimmock Line continued through the rest of 1863. Captain Dimmock wrote that by late in July 1863, the Dimmock Line was “not entirely completed, but sufficiently so for all defensive purposes.” Due to movements by Union troops late in the spring of 1864, the work stopped on the Dimmock Line in time to impede Northern troops.

Artillery Emplacements Outside Petersburg

Union troops moved against Petersburg on June 9, 1864, but were surprised to encounter the Dimmock Line. Poor communication led to most of the Union infantry leaving the Petersburg area having never been seriously engaged. Union cavalry attacked Battery Number Twenty-six, which fell to them; however, a combination of local armed townspeople and the critical arrival of Confederate artillery forced the cavalry to retreat. (The skirmish came to be known as the Battle of Old Men and Young Boys.) While Petersburg residents breathed a sigh of relief, numerous Confederates unleashed their wrath over the design and incompleteness of the Dimmock Line. General Pierre G. T. Beauregard, in charge of the military department that included Petersburg, noted that the Dimmock Line was a “bad system of defensive works.” On June 10, Beauregard ordered more work to the defenses, prompting one officer to note that the line was “still weak” though “much improved.”

The Opening Assaults on Petersburg

Pontoon Bridge Over the James River

By mid-June 1864, Union general-in-chief Ulysses S. Grant had suffered a series of setbacks in Virginia, including the retreat of the Union troops after the Battle of New Market in May, the stalemate that developed at Cold Harbor after June 3, and the failure of Benjamin F. Butler‘s Army of the James during the Bermuda Hundred Campaign. In an effort to take Richmond from the south, Grant and the Army of the Potomac crossed the James River while Major General William F. Smith’s Eighteenth Corps of the Army of the James used ships to get to City Point. From there, on the morning of June 15, 1864, approximately 15,000 to 16,000 men moved against Petersburg. Only 2,200 Confederate troops were positioned in the Dimmock Line on June 15 to oppose Smith. These troops were placed in the eastern defenses.

Black Troops Near Petersburg

Smith began his assault on the Dimmock Line at seven o’clock in the evening. For fifteen minutes, his artillery bombarded a portion of the Confederate line. The infantry stepped off around 7:15. While Batteries Four and Five fell to white Union soldiers and Batteries One through Three were evacuated, the distinctive element of this battle was the action of U.S. Colored Troops commanded by Brigadier General Edward Hinks. These troops captured Batteries Six through Eleven by nine o’clock. Colonel Joseph Kiddoo, commanding the 22nd U.S. Colored Troops, noted in his report that the “officers and men behaved in such a manner as to give me great satisfaction and the fullest confidence in the fighting qualities of colored troops.” By the time the fighting ended, however, Beauregard had increased his numbers with the arrival of a new division and dug in a new position slightly closer to Petersburg.

On June 16, the Confederates lost Batteries Twelve through Fourteen. Ultimately, the Union assaults on June 16 were poorly executed and thus the Confederates held on to their new line for the most part. The following day, at about daybreak, Union troops captured Battery Fifteen. The fighting lasted throughout the day on June 17, but was poorly coordinated by Union forces. That night, Confederates fell back closer to Petersburg and dug a new line that met up with the Dimmock Line at Battery Twenty-Five. Union troops attacked a part of the Dimmock Line on April 2, 1865, but Confederates held on until Petersburg was evacuated that night.

March 1862
The Petersburg Common Council first considers the possibility of a defense line around Petersburg, but no further action is taken.
July 26, 1862
Work begins on a ring of permanent fortifications around Petersburg, soon to be called the Dimmock Line.
July 28, 1862
Virginia and Georgia soldiers alongside enslaved laborers join North Carolinia soldiers in constructing earthworks east of Petersburg.
August 1862
Late in the month, Confederate troops begin leaving Petersburg and enslaved laborers also begin to scatter from the construction sites of the Dimmock Line, a line of defensive earthworks around the city.
August 4, 1862
Confederate engineers Lieutenant Colonel Walter H. Stevens and Colonel Jeremy F. Gilmer arrive to lay out a defense line around Petersburg, but much of the responsibility falls on Captain Charles H. Dimmock's shoulders.
September 8, 1862
Confederate Major General Samuel French requests 150 additional slaves to work on the Dimmock Line, a line of defensive earthworks around Petersburg.
December 12, 1862
Captain Charles H. Dimmock requests 200 more slaves to work between eight and four o'clock daily, with rations provided by the Confederate government and two dollars provided daily to their owners for their services. They are constructing a line of defensive earthworks around Petersburg.
July 26, 1863
Captain Charles H. Dimmock records that the earthworks under construction around Petersburg, while incomplete, are sufficiently complete for the purpose of defense.
April—May 1864
Work appears to stop on the defensive earthworks around Petersburg—the so-called Dimmock Line—due to Union threats near Richmond and Fredericksburg.
June 9, 1864
Union infantry approaches Petersburg but halts in front of Batteries Four, Five, Six, and Seven of the Dimmock Line. Union cavalry attacks Battery Twenty-six but is repulsed by local townspeople, Confederate infantry, and Confederate artillery in what is known locally as the Battle of Old Men and Young Boys.
June 15—18, 1864
Confederate troops on the Dimmock Line around Petersburg lose Batteries One through Twenty in the first four days of fighting, which begins the Petersburg Campaign. Confederate troops consolidate their defense line by building new earthworks and linking them with Battery Twenty-five.
April 2—3, 1865
Confederates evacuate those portions of the Dimmock Line around Petersburg still under their control and join Robert E. Lee's last retreat.
  • Greene, A. Wilson. Civil War Petersburg: Confederate City in the Crucible of War. Charlottesville: University of Virginia Press, 2006.
  • Henderson, William D. Petersburg in the Civil War: War at the Door. Lynchburg, Virginia: H. E. Howard, 1998.
  • Hess, Earl J. In the Trenches at Petersburg: Field Fortifications & Confederate Defeat. Chapel Hill: University of North Carolina Press, 2009.
  • Howe, Thomas. Petersburg Campaign: Wasted Valor, June 15–18, 1864. 2nd ed. Lynchburg, Virginia: H. E. Howard, 1988.
APA Citation:
Dabney, Emmanuel. Dimmock Line, The. (2020, December 07). In Encyclopedia Virginia. https://encyclopediavirginia.org/entries/dimmock-line-the.
MLA Citation:
Dabney, Emmanuel. "Dimmock Line, The" Encyclopedia Virginia. Virginia Humanities, (07 Dec. 2020). Web. 19 Jul. 2024
Last updated: 2020, December 07
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