No. 12. Reports of Col. Thomas W. Cahill, Ninth Connecticut Infantry, commanding Second Brigade, and resulting correspondence.

HEADQUARTERS SECOND BRIGADE,
Baton Rouge, La., August 5, 1862.

CAPTAIN: We are attacked by a very superior force, probably 15,000. They are determined to take the city at all hazards. General Williams is killed and a number of field officers are badly wounded. If it is possible to send us re-enforcements let it be done with all dispatch. The Navy is threatened by the ram Arkansas, which will divert them from our service; therefore if more gunboats can be sent they will be of great use.

THOS. W. CAHILL,

Colonel Ninth Connecticut Volunteers, Commanding.

THOS. W. CAHILL,

Colonel Ninth Connecticut Volunteers, Commanding.

Attacked this morning at 3.45 o'clock. Breckinridge lost his right arm. Lovell killed. Colonel Allen, Captain Chinn, of Baton Rouge, and a lieutenant killed. This is reported by all the prisoners taken. Our loss 250, including General Williams and several officers. Reported that we lost two guns and captured three. Last report is that we have lost no guns and have repulsed the rebels. Expect another attack to-night or to-morrow morning. William Blount, captain of artillery, from Texas, says Lovell is not present. Thinks rebel loss greatest.

HEADQUARTERS SECOND BRIGADE,
Baton Rouge, La., August 6, 1862.

CAPTAIN: I have the honor to report that an attack was made early yesterday morning by a Confederate force of about ten regiments, under command of Major General J. C. Breckinridge, and that after a fight of four hours' duration and of great severity the enemy was repulsed. I regret to state that Brigadier-General Williams was killed on the field by a rifle-ball through the chest. During the battle our forces were obliged to retire about a quarter of a mile from our original position, and the enemy were thus able to occupy temporarily the camps of the Twenty-first Indiana, Seventh Vermont, and Fourteenth Maine Regiments, and to destroy much of the baggage and camp equipage. They were, however, driven out, but our number being much lessened by sickness, and the men on the field being much exhausted by fatigue and heat, it was deemed inexpedient to pursue. I am unable as yet to give a report of our casualties, which I am sorry to say are considerable.

The enemy has retired several miles, and from all I can learn are still retiring. I am expecting it possible they may receive re-enforcements, and am disposing my troops in the strongest positions. Our force engaged numbered less than 2,500. The enemy had at least 5,000 with twelve or fourteen field pieces and some cavalry.

The ram Arkansas approached with the intention of engaging our gunboats, but grounded above the point at a distance of about 6 miles, and to-day was engaged by the iron-clad Essex and destroyed.

Inclosed is a copy of a communication received by a flag of truce from Major-General Breckinridge and my reply thereto. You will see by the latter that Brigadier-General Clark and his aide-de-camp