John Dimitry , A. M., Confederate Military History, a library of Confederate States Military History: Volume 10.1, Louisiana
Clement Anselm Evans, Ed.

The Confederate loss at Baton Rouge was 446 killed, wounded and missing. The contest had been stubborn and had involved much close fighting, in which both armies suffered considerably. The loss of the enemy, partially given, was believed to be about the same. Had it been infinitely smaller, the death of Brig.-Gen. Thomas Williams alone, put against heaviest statistics of casualties, would have weighed the balance down. The death of that excellent soldier proved a serious loss to their army. The enemy was superior both in numbers and artillery, and the battle was marked by other sharp disproportions—4,500 Federals¹ (Butler's estimate June 1st) against 2,600 Confederates—no less than 18 pieces of field artillery, exclusive of the guns of the fleet, against 11 pieces—Federals fresh and well-clothed, against Confederates foot-sore with marching from the Comite, many of them weak from sickness, in rags and on indifferent food. Although the Federals held the city, their occupation of it told the tale of defeat. On the 20th of August, Confederate scouts drove in their pickets. On the 21st the Federals evacuated Baton Rouge.

Both armies had claimed the battle of Baton Rouge on August 5th. The evacuation by the enemy, two weeks after the battle, justified the Confederate claim. This withdrawal from Baton Rouge was the result of certain skillful operations by that dashing tactician, Major-General Van Dorn. He had already clearly seen the importance to the Confederacy of the occupation of Port Hudson. With that in view, he had ordered an immediate movement toward the place. He had selected that point specially for its eligibility for defense, and for its capacity for offensive annoyance to the enemy. Baton Rouge would, in the meanwhile, be held in menace. The event justified Van Dorn's military foresight. The enemy disappeared from the Mississippi between Baton Rouge and Vicksburg.