Nor was this all, for at the grand review and inspection by General Williams on July 31, of the 140 members of the battery only 21 were present for duty, the remainder, including Captain Nims himself, being in the hospital. The same condition naturally prevailed among the other members of the brigade, one regiment (the 7th Vermont) mustering but 48 men and other regiments averaging 150; so that not one half of the entire number was reported as ready for service.
When this state of affairs was made known to Major Van Dorn of the Confederate Army, he organized an expedition to capture the post. It was composed of about 5000 men under Gen. J. C. Breckenridge who expected to be aided in his endeavor by the ram _Arkansas_. With his entire force moving along the two roads that enter Baton Rouge from the southwest he made a vigorous attack in the early morning of August 5. Williams was expecting the attack (we read in the diary of one of the men that the horses had been standing in harness three days and three nights), and had arranged his forces to meet it. His army, depleted as it was by sickness, numbered only 2500 effective men. He posted the 4th Wisconsin on Bayou Gros on the extreme left, with a portion of Manning's Battery in the arsenal grounds on its left. On the right of that regiment was the 9th Connecticut with four of Manning's guns in the cemetery. To the left of Greenwell Springs Road was the 14th Maine and next came the 21st Indiana with four guns of Everett's Battery. The 6th Michigan was posted across the country road with two guns. In the rear of the last two was the 7th Vermont, and at the extreme right was the 30th Massachusetts supporting Nims' Battery.[3]
Owing to the illness of Captain Nims, First Lieutenant Trull was in command, while to take the place of the men in the hospital a detail of thirty men had been secured from the 9th Connecticut so that when the battle opened the six guns were manned.
The conflict lasted from four to nine o'clock, a period of five hours, and throughout the entire battle Nims' Battery won the highest commendation for efficient service. Perhaps nothing could give a better account of what it accomplished than the Official Report of Colonel Dudley:[4] "I immediately ordered Nims' Battery under the command of the brave and efficient First Lieutenant Trull, to the left and considerably to the front so as to clear the thick woods in its front. This battery went into action within 250 yards of a Kentucky regiment sheltered by a fence and a cornfield, where it remained doing excellent service until ordered to change position. Officers and men could not have behaved better. More coolness could not have been expected from veterans than the officers and men of this battery displayed. They changed position four times under my own observation and on each occasion the gallant commander displayed his competency for the prominent part he acted in this severest part of the field.... At one time the undaunted Trull with his battery was hotly engaged on the right with a full battery of the enemy which had approached within 150 yards (supposed to have been the celebrated Simmes' Battery), but the 6th Michigan moved up to the support of Nims' Battery in elegant order. Its assistance came most fortunately for it was clear the enemy intended to outflank us at this point.... At this juncture of the conflict I ordered Lieutenant Trull to fire his three left pieces across the fronts of the Indiana 21st, Massachusetts 30th, and 7th Vermont. This was the turning point of the right wing. The galling fire of canister effectually silenced the enemy's fire and they retreated to the rear."