Numbers 9. Report of Colonel Nathan A. M. Dudley, Thirtieth Massachusetts Infantry, commanding Brigade, of engagement on the La Fourche, near Donaldsonville.

BIVOUAC NEAR DONALDSONVILLE, LA.,

July 15, 1863.

CAPTAIN: I have the honor to submit the following report of the re-cognisance made by the Third Brigade, on the 12th and 13th instant, by order of Brigadier-General Weitzel, commanding division:

Besides my own brigade, which consisted of the Thirtieth Massachusetts Volunteers, One hundred and sixty-first and One hundred and seventy-fourth New York Volunteers, there were temporarily assigned me two sections of the Sixth Massachusetts Battery, First Lieutenant Phelps commanding, and Captain Barrett's company of cavalry.

At 3 p. m. on the 12th instant, I sent in advance, down the right side of Bayou La Fourche, a small force of cavalry, followed by four companies of infantry, under Captain Shipley, Thirtieth Massachusetts Volunteers, the balance of the force following in order by the flank, with cavalry scouts constantly out on my right.

Previous to starting, I had an interview with Colonel and Acting Brigadier-General Morgan, commanding brigade, Emory's division, who stated that he was ordered to follow down the opposite side of the bayou with his brigade. We arranged signal flags, to be used in case of necessity, before separating.

The advance skirmishers had not proceeded more than 1 miles before the enemy opened a brisk fire upon them, driving in the cavalry to the infantry support. The enemy's pickets being well supported by a dismounted force, in full view, I ordered Lieutenant Phelps to bring up one of his pieces, and, after four or fire shots, they fell back, keeping up a fire from both sides of the bayou as we advanced. When about 1 mile from Kock's plantation, I halted till Colonel Morgan came up on the opposite side, when the tow columns moved forward nearly abreast up to Kock's residence, when I made the following disposition of my forces: One section of Phelps' battery I placed on the road fronting down the bayou, supported on the left by two companies of infantry, on the right by the One hundred and seventy-fourth and One hundred and sixty-first New York Volunteers, the latter under Colonel Harrower and the former in command of Major Keating. These two regiments were in line of battle, the right of the One hundred and sixty-first extending down a broad lane,with a clear field in front about 100 yards wide. Three-fourths of a mile to the right I posted two companies from the One hundred and sixty-first, to prevent a surprise on that flank. With strong pickets on the road running down the bayou, and at right angles to it, with mounted vedettes in front, I felt certain of no surprise.

The Thirtieth Massachusetts Volunteers were posted as a reserve near Kock's house, in of battle, with the exception of two companies, which were stationed with pickets out on the flanks, at the junction of a plantation road and the Bayou road, with the remaining section of Phelps' battery. By this disposition, I had command of both roads running to the right; protection to my rear and front, with Colonel Morgan's command on the left. This was my arrangement of the force for the night of the 12th.

About 6 o'clock in the evening, the enemy opened a brisk skirmish in front, and exchanged a few shots with our artillery.