The Confederate defensive line was centered on a powerful group of cannon positioned on Mill Creek Ridge, including Courtney's, Raine's, Rice's, and Lusk's batteries, while the Baltimore Light Artillery under Capt. John B. Brockenbrough held the far left. From this high ground, the gunners had a commanding field of fire. Courtney's Battery first unlimbered and opened fire on Union troops pursuing the 15th Alabama, and as Federal forces deployed in greater strength, including artillery, Ewell added the other batteries to create a daunting mass of defensive fire. Around 10 a.m., cannon on both sides began firing, starting with scattered blasts and quickly rising to a thunderous roar. Near Union Church, New York Times reporter Charles H. Webb wrote that "The diabolical precision with which shot and shell were instantly pitched at us exceeded anything I had before imagined." The gunners also helped repel Union infantry, and one Federal soldier said the "screaming and hissing shells... as thick as leaves." During one Union advance, Confederate Lt. Joseph Latimer asked an officer to delay moving forward so he could first "give them a few more rounds" of canister. Positioned behind the crest of the ridge, the gunners were shielded from direct Union cannon fire, though higher-arcing shells still inflicted casualties, including one of Latimer's sergeants, who was struck in the head by a shell. The bombardment also endangered infantry supporting the guns; Irby G. Scott of the 12th Georgia said, "Solid shot, grape, and bombs seemed like they were raining down upon us," and a single shell killed or wounded nine men. By the end of the battle, Federal troops had failed to reach Mill Creek Ridge, due in significant part to the Confederate artillerymen who held their position throughout the long day.