On June 12, 1864, General Grant ordered his army to make a move to the south with the city of Petersburg being the target. General Robert E. Lee was caught off guard; when the Union army crossed the James River to attack Petersburg before he could send reinforcements down to defend the city. When the Union army failed to capture Petersburg, Grant ordered his men to cut off all the Confederate supply lines to the city.
Soldiers on both sides engaged in a different form of warfare than they had witnessed during the previous three years of war because of the prolonged siege that ensued. For nine-and-half months, soldiers were entrenched in the fields and forests around Petersburg. They ate, slept, fought, and lived in trenches that they dug to protect themselves.