HEADQUARTERS, NINTH DIVISION,
Big Black River Railroad Bridge, Mississippi, June 4, 1863.

GENERAL: I have the honor to acknowledge the receipt of your favor of yesterday, with orders and instructions relative t a rebel force at Grant's house, I immediately sent all the available cavalry force (three companies Sixth Missouri) in that direction, with orders to proceed, as far as practicable, with a view to make a connection with Colonel Johnston's column, and to gather all the information in regard to ferries and fords across Big Black, and further, in regard to any attempt of the enemy's advance. The party has just returned, and reports that the rebel Major [W. AL] Rorer, with the Twentieth Regiment Mississippi Infantry (mounted),600 strong, had been encamped on the Benton road from Vicksburg, at the bridge across Bear Creek, about 1 mile east of where General Blair was encamped, at Major Hain's place. From Cap. Tom Jones (a dangerous rebel who in my prisoner, and who I will forward to the headquarters) we learn that the above force was the only one in the immediate vicinity, and that it was the same which was at Grant's house. There are several fords north of the Bridgeport Ferry which are now practicable; one ford is between the latter and the Birdsong Ferry, the other below Bush Ferry. From the description of the location of the above-mentioned secesh camp and the situation of these fords, I ma inclined to think that the Twentieth Mississippi, which fired a few days ago considerably below Raymond, Bolton, and Brownsville, crossed at these fords, and it would be very desirable to have a flying column established between Bush's Ferry (Oak Ridge) and Bridgeport Ferry to interrupt such raids. I am also informed that the rebel General Walker was crossing his DIVISION yesterday at Kibby's Ferry (I believe it the same as Cox's Ferry) to make a reconnaissance, but that Joe Johnston was not yet prepared to advance. The party sent out yesterday night did not learn anything of Colonel Johnson. There seem to be a number of rebels squads running all over the country in my front and on my right (across the river). Yesterday a patrol of the THIRD Illinois fell in with about a dozen men. My men were returning form Champion's Hill, and round the rebels on the road east of Edwards. They fired, and the rebels turned north, giving my men the road. Another patrol, under Captain Miller, sixth Missouri Cavalry, ordered to go by Edwards to Bridgeport, met about 25 rebels mounted on mules. They attacked them and unsaddled one, bringing in mule and saddle. From contraband source I heard yesterday that a regiment of Tennesseans were marching toward Baker's or Fourteen-Mile Creek. I at once sent a company of cavalry to Baldwin's Ferry, but on returning, the commander reported everything quiet in that direction. The Eighty Kentucky (rebel) under Lyon, marched yesterday morning at 3 o'clock through Edwards, taking some of the paroled poisoners (rebel) away.

I am general, with the highest esteem, your obedient servant,

P. JO. OSTERHAUS,

Brigadier-General, commanding.

Major General U. S. GRANT,

Commanding Department of the Tennessee.