On the days leading up to the battle, Grant sent his men out on special raids to attack Confederate camps. The catalyst for the larger battle finally ensued when Confederate soldiers encountered a union picket. A firefight soon broke out. Hearing the firefight, a Confederate soldier named Stephen Lee took to the highest point he could get to: Champions Hill. After being notified about what was happening, he saw the Union forces coming into the field. Knowing the strategic importance that the hill could play, both sides tried to seize and keep control. The battle went back and forth until the Union finally turned that tide and took Champion Hill.
There is a sign that is standing where some of the battle took place. It has a quote from Alvin P. Hovey on it. A part of this quote says Literally the hill of death: men, horses, cannon, and the debris of an army lay scattered in wild confusion. Hundreds of the gallant Twelfth division were cold in death or writhing in pain, and, with large numbers of Quinby's gallant boys, lay dead, dying, or wounded, intermixed with our fallen foe. The sight and the horror that must have been surrounding all of these men seems unfathomable, but with this horrific battle won, Grant's legacy was cemented.
To learn more about the battle in greater detail, go to the paper written by Jon Stephenson. The official website also gives more information, tells about reenactments, and other special events.