Throughout the Seven Days Battles, Longstreet had operational command of nearly half of Lee's army—15 brigades—as it drove McClellan back down the Peninsula. Longstreet performed aggressively and quite well in his new, larger command, particularly at Gaines's Mill and Glendale. Lee's army in general suffered from poor maps, organizational flaws, and weak performances by Longstreet's peers, including, uncharacteristically, Stonewall Jackson, and was unable to destroy the Union Army. Moxley Sorrel wrote of Longstreet's confidence and calmness in battle: "He was like a rock in steadiness when sometimes in battle the world seemed flying to pieces." General Lee said shortly after Seven Days, "Longstreet was the staff in my right hand." He had been established as Lee's principal lieutenant. Lee reorganized the Army of Northern Virginia after Seven Days, increasing Longstreet's command from six brigades to 28. Longstreet took command of the Right Wing (later to become known as the First Corps) and Jackson was given command of the Left Wing. Over time, Lee and Longstreet became good friends, and set up headquarters very near each other. Despite sharing with Jackson a belief in temperance as well as a deep religious conviction, Lee never developed as strong a friendship with him. Piston speculates that the more relaxed atmosphere of Longstreet's headquarters, which included gambling and drinking, allowed Lee to relax and take his mind off the war, and reminded him of his more happy younger days.