When finished, the chain of breastworks and artillery emplacements around Petersburg was 10 miles long. It began and ended on the Appomattox River and protected all but the northern approaches to the city. The 55 artillery batteries were consecutively numbered from east to west. Although natural terrain features were utilized whenever possible, some glaring weaknesses existed. For example, between Batteries 7 and 8 lay a deep ravine which could provide a means of penetration by an attacking force. The very length and size of the fortifications proved to be a disadvantage. It meant that a larger number of troops would be necessary to defend the line than General Beauregard, charged with this heavy responsibility, had present for duty. Col. Alfred Roman, an aide-de-camp of Beauregard, estimated that the long “Dimmock Line” would take more than 10 times as many men to defend as were available. [Illustration: _Gen. P. G. T. Beauregard, who held the Confederate defense line before Petersburg until Lee arrived._ Courtesy, National Archives.] The first serious threat to the untested line occurred when the Army of the James was dispatched to approach Richmond from the southeast by way of the James River. Although, the Army of the James was soon neutralized by being bottled up in Bermuda Hundred by a smaller Confederate force, it would be wrong to assume that the Union force was completely out of the picture. It not only immobilized a considerable number of Confederate soldiers assigned to guard it, but it provided a reservoir of troops for operations in other parts of the field. On several occasions raids were made on the railroads south and west of Petersburg. The most serious of these occurred on June 9, 1864, when 3,000 infantry and 1,300 cavalry appeared in force along the eastern sector of the Dimmock Line. The infantry contented itself with a menacing demonstration, but the cavalry attacked on the Jerusalem Plank Road. It was halted by the joint efforts of regular Southern Army units assisted by a hastily summoned home guard of old men and youths. The damage done by raids such as this was quickly patched up, but they were a constant nuisance to the city’s transportation lines. To shut off permanently the supplies that streamed along the railroads, the Union commanders realized that it would be necessary to take permanent physical possession of them. _The Battle of Petersburg, June 15-18, 1864_ After the Battle of Cold Harbor on June 3, Grant had abandoned, for a time at least, his plan to capture Richmond by direct assault. With characteristic zeal he had ordered Meade to move the Army of the Potomac across the James River and to invest the more southerly city. On June 14 Grant and Butler conferred at Bermuda Hundred. At that time orders were given for the attack on Petersburg.