Complex sentence: Sporadic skirmishing and artillery fire continued until 3 a.m. Wary of Tracy's Brigade to the north, McClernand posted Brigidier General Peter J. Osterhaus's 9th Division facing that direction.
Split into simpler sentences: Sporadic skirmishing and artillery fire continued until 3 a.m. Wary of Tracy's Brigade to the north, McClernand posted Brig. Gen. Peter J. Osterhaus's 9th Division facing that direction.