Late in August, when it was learned that a movement against Lexington, on Missouri River, was about to be made by a strong Confederate force under General Price, measures were taken to reinforce the small garrison and prevent the place from falling into the hands of the enemy. The Twenty-third Illinois Regiment, Col. James A. Mulligan, which was called "the Irish Brigade," was ordered thither from Jefferson City, and other reinforcements were promised. Mulligan, with his command, set out at once, marched nine days, foraging on the country, and on reaching Lexington found there a regiment of cavalry and one of home guards. The next day the Thirteenth Missouri Regiment, retreating from Warrensburg, joined them. This gave Mulligan a total force of about two thousand eight hundred men, who had forty rounds of ammunition, and he had seven field-guns and a small quantity of provisions. He took possession of the hill east of the town, on which stood the Masonic College, and proceeded to fortify. His lines enclosed about eighteen acres, and he had put but half a day's work on them when, in the evening of September 11th, the enemy appeared. In the morning of the 12th the fighting began, when a part of Mulligan's men drove back the enemy's advance and burned a bridge, which compelled them to make a detour and approach the place by another road. Again Mulligan sent out a detachment to check them while his remaining force worked on the intrenchments, and there was brisk fighting in the cemetery at the edge of the town. In the afternoon there was a lively artillery duel, and the National forces held their own, dismounting a Confederate gun, exploding a caisson, and causing the enemy to withdraw at dusk to a camp two miles away. The next day the garrison fitted up a small foundry, in which they cast shot for their cannon, obtained powder and made cartridges, and continued the work on the intrenchments. The great want was provisions and water. In the next five days the Confederates were heavily reinforced, while the little garrison looked in vain for the promised help.