Thanks for the additional info - there were indeed three other mine-works attempted during the siege of Vicksburg - simultaneously - none were very effective and all were known to be underway by the Confederates who were also counter-minig at the same time. This occurred during late May 1863. Petersburg was almost a month after the fall of Vicksburg, 4th July 1863. General Grant was in command of both armies, Vicksburg and Petersburg, at the times but was not the general-in-chief of the US Army until early 1864. I have not seen any comments from him re' the Vicksburg aasault - tho' Lincoln did make a degrading comment of Pemberton (according to Grant's aide, General Porter), one of the commanders defending Vicksburg after he failed to halt the siege. Pemberton was only outnumbered about 110,000 to < 50,000. Grant's army still took first prize in casualties and foul-ups in general (no pun). Lack of supplies, reinforcements, and exhaustion took their toll - not lack of courage. Fortunately, in the end, the tear in the national fabric was repaired. I believe this is very pertinent in our descendancy -- across the board.