> Pemberton’s report-
> …During the evening and night of this day [Dec 27] Brigadier-Generals Vaughn and Gregg, with their brigades,
> arrived from Grenada, and also Brig. Gen. [Seth M.] Barton and his brigade, of Maj. Gen. [Carter L.] Stevenson’s
> division. Before daylight they were moved to the front.

Of note here is the fact that Vaughn and Gregg, the only two units from Grenada to reach the field of battle, were ordered south before Pemberton realized that Grant was returning to Memphis. This means that Van Dorn's raid had no effect on the battle itself, a substantial deviation from the traditional history of the Battle of Chickasaw Bayou.