Osawatomie, Battle of.—During, the early summer of 1856, armed bands of both free-state and pro-slavery men were traversing the eastern part of the territory and several encounters took place between the two factions. Soon after the sack of Lawrence (q. v.) the pro-slavery men decided that every free-state settler must be driven out of the territory, and Osawatomie was chosen as one of the places for the exhibition of this policy. The residents feared that the whole settlement, the Browns more particularly, would be destroyed. Early in June a party of 150 Missourians, under command of John W. Whitfield, learning that most of the men of the free-state forces were occupied elsewhere, attacked the town. No resistance was made, and beyond plundering some houses and running off horses no great damage was done. From that time on, however, the residents were in hourly fear, as the territory from Mound City to Fort Scott and as far west as Lawrence was occupied by border ruffians and neither person nor property was safe. About the middle of Aug., 1856, the Missouri-Kansas militia began plundering and killing in the vicinity of Osawatomie. On the 25th about 150 Missourians camped not far from the town expecting to take it by surprise. While they were quick, the free-state men were quicker, the camp being captured after a total rout of the ruffians. It was not anticipated that another attack would soon be made, but on the night of Aug. 29 a band of about 400 Missourians, commanded by Gen. Reid, started from Bull creek for Osawatomie, intending to reach the town about midnight and make an attack about daylight.

On the morning of Aug. 30 Frederick Brown left Osawatomie before sunrise to return to Lawrence, and while on his way to S. L. Adair's, met Reid and a small advance guard, which was being guided by a minister named Martin White. The attacking forces had crossed the Marais des Cygnes at Bundy's ford, about 4 miles northwest of Osawatomie, and was approaching the town when Brown was recognized by White, who raised his rifle and shot Brown upon the spot. The shot aroused some of the settlers living in the vicinity, messengers were at once despatched to notify the people in the village and Capt. Brown, who was half a mile east of town. Dr. Updegraff and Capts. Brown and Cline collected their men as quickly as possible and decided on plans for defense. At first it was designed to use the blockhouse, but on learning that Reid had a cannon with him this plan was abandoned. Brown, with 41 men took a position in the timber on the south side of the Marais des Cygnes, facing south. Brown, with 17 men, was on the right; Dr. Updegraff, with 10 men, formed the center, and Capt. Cline, with 14 men, the left wing of the defending company. An independent company was still farther to the left in the Emigrant Aid company's mill. By the time these forces were arranged the Missourians were passing about 600 yards in front. One man, who had been sent to reconnoiter, finding the enemy so close, had fired at them. He immediately retreated to the main body, followed closely by the Missourians, who formed on the ridge west of where the John Brown monument now stands. After forming in line they fired three guns as a signal for the free-state men to surrender. Orders had been issued to the defenders not to fire until Capt. Brown gave the signal, but when they heard these three shots they could not be restrained, believing that the enemy had opened the engagement. All of Brown's command fired, although the men knew it was contrary to orders. The Missourians first attacked the right wing and were partially repulsed, when they brought the cannon into action about 400 yards in front of Brown's command, moving it further east at each shot, to scour all the timber. It was loaded with grape shot, but the bullets passed over the heads of the men and little damage was done. The free-state forces kept moving eastward, firing at the enemy, who finally abandoned the cannon, dismounted and charged into the timber, whence the main body of the defenders was located. After having held the ground for over an hour against ten times their number, the free-state men were now placed in a position where they must surrender or retreat, and most of them escaped across the Marais des Cygnes, losing a few killed or taken prisoners. The Missourians then entered the town and commenced to pillage and burn it. They first fired the blockhouse, in which several men were stationed, and only four houses escaped being destroyed. When the ruffians left they had two wagons filled with their wounded and ten loaded with the plunder taken from the homes of the citizens.

Reid and his force started east, with the intention of crossing the Marais des Cygnes near the mill, but the men stationed there opened fire, and not knowing the number of the defenders, the Missourians faced about and left the town by the way they came. The free-state men who escaped assembled at a log house north of the river, among them being Brown and Updegraff. The following day they moved to the south side of the Marais des Cygnes and commenced fortifying another camp, but it was never completed.

The free-state men lost about six men killed or captured, and several more were seriously wounded. It is supposed that the Missourians suffered about the same number in dead and wounded, although it was never definitely known.