Early in December the command marched to Houston, thirty miles northeast of Hartsville, where it remained a month.
On the 7th of January, 1863, General Brown, who was in command of the Union forces at Springfield, learned that General Marmaduke, with an army of 4,000 men was on the march to make an attack upon that place. He at once called on General Warren, who was eighty miles distant from Springfield, for reënforcements. Colonel Merrill was sent with about 1,000 men from the Twenty-first Iowa, Ninety-ninth Illinois, Third Iowa Cavalry, and the Third Missouri cavalry, with two pieces of artillery. The command started on the 9th, marched twenty-two miles and camped for the night on Beaver Creek. Long before daylight the next morning the march toward Hartsville was resumed, when the news came that a large force of the enemy had occupied that place the night before. A reconnaissance was made while the command halted to learn the result. No enemy being found Colonel Merrill pushed on, going into camp on the night of the 10th within eight miles of Hartsville and but one mile from a Confederate encampment. Early the next morning, it was discovered that a large force of the enemy was approaching from the direction of Springfield. This proved to be the advance of General Marmaduke’s army, which had been defeated by General Brown in an attack upon Springfield a few days before. Colonel Merrill formed his men in line of battle and kept up a warm fire on the advancing Confederates for an hour, holding them in check, while the main body occupied the town. About eleven o’clock Merrill advanced upon Hartsville, and placing his artillery on a commanding ridge made his dispositions for the battle. The Twenty-first Iowa, under Lieutenant-Colonel Dunlap, held the left, the Illinois infantry was on the right, with the cavalry on the extreme left, all sheltered by a dense growth of brush. General