To counteract the effect of the Free-State victories, heretofore referred to, and to restore pro-slavery supremacy, a pro-slavery army numbering more than a thousand men, led by Major General David R. Atchison, invaded the Territory. This formidable force left Westport August 23d, and on the 29th arrived at Bull Creek, thirty miles from Lawrence. To oppose it, the Free-State army was being mobilized under the command of General Lane; who sent an urgent message to Brown, and others at Osawatomie, asking them to report to him at Lawrence at once, and take part in the impending battle. The message was delivered to Brown by Alexander G. Hawse, on the evening of August 29th, as he approached Osawatomie, "in a cloud of dust and driving the motley herd" of stolen cattle "before him." Captain Shore received a similar request, and promptly responded to the urgent call. He started for Lawrence about three o'clock in the afternoon. Brown did not go. He could not be expected to abandon the horses, and the cattle, and the plunder which he had on hand; and the robber combine of which he was the head, and which was operating so successfully, and which had before it a future so promising. He was too busy. Besides, the troubles about Lawrence would be "water upon his wheel." He was doing business under cover of the distracting conditions then existing. Mr. Villard says, "After consultation, it was decided that the call should be heeded on the next day." At the time Brown received this message, General Atchison had already detached two hundred and fifty mounted men, with one field piece, to march against Osawatomie and burn the place. The command of the expedition was given to Brigadier General John W. Reid, who had served in the war with Mexico. Reid made a night march from Bull Creek. Arriving at Osawatomie, he immediately began his attack. His official report of the fight is as follows:[193] Camp Bull Creek, Aug. 31st GENTLEMEN:--I moved with 250 men on the Abolition fort and town of Osawatomie--the headquarters of Old Brown--on night before last; marched forty miles and attacked the town without dismounting the men, about sunrise on yesterday. We had a brisk fight for an hour or more and had five men wounded--none dangerously--Capt. Boice, William Gordon and three others. We killed about thirty of them, among the number, _certain_, a son of Old Brown and almost certain Brown himself; destroying all their ammunition and provisions, and the boys would burn the town to the ground. _I could not help it_.... Your friend, REID.