Glenn W. LaFantasie, "Oates, William Calvin," American National Biography Online, February 2000, http://www.anb.org/articles/05/05-00576.html.
Oates was given command of the Fifteenth Alabama in the spring of 1863. His commission as a full colonel was delivered to Lee, but for reasons not known it was never confirmed by the Confederate Congress, which meant that technically Oates never achieved a rank higher than lieutenant colonel.... Nevertheless, the Fifteenth Alabama held Oates's loyalty and fondness, for, as he declared later in his life, "there was no better regiment in the Confederate army." At Gettysburg, on 2 July 1863, Oates was in command of his regiment for the first time in battle. On the slopes of Little Round Top, Oates and his Alabamians tried to dislodge the Union defenders of the hill, the Twentieth Maine Regiment under the command of Colonel Joshua Lawrence Chamberlain. After an hour of desperate fighting, some of it in hand-to-hand combat, Chamberlain led his troops in a bold bayonet charge that swept Oates's Confederates from the hillside. "We ran," Oates later confessed, "like a herd of wild cattle." In the rush of retreat, he had to leave behind his brother John, who had been mortally wounded in the fighting.