JUNE 23, 1863. -- Attack on Pawnee Agency, Nebr.

SIR: I have the honor to report that the Sioux (supposed to be Brules) attacked the agency yesterday, killing several Pawnees and wounding myself. I ordered First Lieut. Henry Gray to follow them with 36 men, and, if practicable, to attack them. After pursuing about 50 of them for about 15 miles, he came upon about, 400 or 500 drawn up in line ready to receive him, and upon being assured that the Pawnees, who were with him, 300 or 400 strong, would fight with him, he threw out some skirmishers, when the Sioux opened upon them with rifles, killing Sergt. Joseph Dyson, and mortally wounding Private George Osborn; also killing their horses. At the first fire the Pawnees ran, leaving our men alone. Lieutenant Gray fought them about an hour, when they retreated. Four or five Sioux were killed and several horses. I had started to his assistance with 20 men and one howitzer, which I was compelled to send back, owing to the roughness of the country. When I reached Lieutenant Gray, the Sioux were still in force about 6 miles distant; but it being nearly night, I determined not to attack them, and fell back to my camp.

To better protect the whites living at the agency, I have crossed the Beaver and established camp near the agency, where I shall remain until I receive further orders.

Very respectfully,