FEBRUARY 4-8, 1864.-Expedition from Helena up White River, Ark.

Report of Captain Charles O'Connell, Fifteenth Illinois Cavalry.

HELENA, ARK., February 7, 1864.

SIR: I have the honor to submit the following report of scout up White River: I embarked on steam Cheer February 4, 1864, at 8.50 a. m., in command of 100 men Fifteenth Illinois Cavalry, 40 Third Arkansas, African Descent, Captain Robinson, and 7 men, with one piece of artillery, Lieutenant Hadlock. Left Helena 9 a. m., proceeded toward Friar's Point, destroyed one flat-boat; arrived at Friar's Point 11 a. m.,; found four cotton-boats there. The gun-boat had been ordered to Memphis.

In your dispatch to Captain Bron, of gun-boat, you wanted the steamer White ordered to Helena. I took discretionary power to order all of them to report to your headquarters, as I thought that they could easily captured by the rebels, as they had no gun-boat to protect them. I then proceeded on; arrived Island 63 at 12 m., delivered dispatched; passed gun-boat Eastport at Island 65, the steamer Rike alongside; arrived at Island 66 at 2.20 p. m. The steamer Emerald with troops stopped to wood; had no dispatch for the officer commanding island; arrived at mouth of White River 6 p. m., reported to Captain Prichett, delivered dispatch, disembarked cavalry, and remained at the mouth of White River until morning, as it was not safe to run up at night.

February 5, embarked and moved up White River at 8.30 a. m., no convoy going up; stopped at 12 m. on west side; took three cords wood; arrived at the mouth of Big Creek, 3 miles below Indian Bay, at 5.30 p. m.,; distance down Mississippi, 95 miles; White, 74 miles; disembarked cavalry to feed and water; took two cords wood. I got information that Mayo's and Davis' companies had gone to General McRae's headquarters; embarked and proceeded up Indian Bay at 12.30 a. m., arrived at Indiana Bay Landing 2.30 a. m.; disembarked and left Captain Robinson, Third Arkansas, African Descent,in command of the boat, with orders to remain twenty-four hours at the landing; then, if he did road; arrived at Boyce's, 8.30, February 6, 1864; got positive information that Mayo's and Davis' companies had gone to McRae's headquarters, to organize into a battalion to return his about ten days. Fed hourses and breakfasted at Boyce's; examined his papers and letters. He informed me that he had one revolver, and had fifteen bales of cotton up star is hid from the rebels. They had been encamped on his place. I took his revolver, but did not arrest him, as I could not get information that he had been giving aid to the rebels. They took it. He is coming to Helena to report in a few days.

While there got information that Casteel's company was encamped 3 1\2 miles from Boyce's. I started immediately for his camp, got within one-half mile of it. Met a negro that had just returned from the picket, informing them that we were in the country. I arrested him and made him pilot me to the camp. I found their pickets about 10 rods from their camp, on the opposite side of a cypress swamp; could see their men, about 18, in line, mounted. We fired at the picket, and then charged for them. We could only go