Complex sentence: Pemberton directed William W. Loring to send forces from the southern area of the line (where they were only lightly engaged with McClernand's ineffective attack) to reinforce the Hill, but Loring refused, citing a strong Union presence to his front.
Split into simpler sentences: Pemberton directed William W. Loring to send forces from the southern area of the line, where they were only lightly engaged with McClernand's ineffective attack, to reinforce the Hill. However, Loring refused to budge, citing a strong Union presence to his front.