In the early morning of 30 July 1864, as Confederate troops lay sleeping not far from Petersburg, Virginia, a huge explosion rocked them from their sleep. Men and guns were tossed into the air like toys, with the blast killing around 270 soldiers. When the smoke cleared, a giant crater (170 feet long, 100 feet wide, and 30 feet deep) left a breach in the Confederate lines.
The explosion and the resulting crater were the handiwork of Union forces—in particular the 48th Pennsylvania Infantry, largely composed of former coal miners. They had dug a mine 500 feet to the Confederate lines then ignited 8,000 pounds of gunpowder, hoping the resulting Confederate confusion would give Union troops the badly needed advantage that would allow them to end the month of trench warfare and finally capture Petersburg.
Unfortunately for the Union, the explosion was the only thing that went according to plan.
After the explosion, the Northern troops were supposed to immediately rush around the crater and take advantage of the hole in Confederate lines. But due to a last minute switch, the African American troops, who had been training for weeks to lead the charge, were replaced with a different division, who weren’t well-informed about what they were supposed to do. These troops waited 10 minutes after the blast to head toward the Confederates, and then they ran into the crater instead of around it. Once in the hole, they got trapped by the sandy ground and steep sides, allowing the Confederates to easily pick them off in what one Southern general called a “turkey shoot.”
Other Northern troops, who came at the Confederates from the sides, managed to gain some ground but were eventually repulsed, and the Union forces fled back to their own lines. When the day’s fighting was done, 3,800 of the Union’s 8,500 troops were killed, wounded, or missing, compared to the South’s 1,500 out of 6,100 (the majority of their 360 deaths had been incurred in the crater explosion).
The two sides would remain bogged down in the trenches for another nine months, until Robert E. Lee’s Southern troops were finally forced to retreat and he surrendered at Appomattox Court House in April the following year.