Our camp at the spring was broken up on the afternoon of September 15th, when we moved southward to Freeman's ford, where we crossed the Rappahannock and took up a position between Culpepper and Stone House mountain. The whole army was now in position between the rivers Rappahannock and the Rapidan.
About the end of September the 11th and 12th corps were detached from the Army of the Potomac and under General Hooker were sent to the west to reenforce our army operating around Chattanooga, Tenn. Longstreet's corps of the rebel army had previously been sent to the same point to reenforce General Bragg.
We remained in the vicinity of Culpepper until October 12th, when it was found that Lee's army had crossed the Rapidan and was turning our right. This caused a retrograde movement of our whole army. Our division moved to the rear on October 11th, the 57th acting as flankers on the left of the column. At one point, when on a high hill, we had a fine view of a cavalry battle which was going on in our rear near Brandy Station. In the evening we crossed the Rappahannock at Freeman's ford and halted for the night in a pine woods. On the morning of the 12th we learned that the enemy had driven back our cavalry, and was crossing the river at our old camp at Sulphur Springs, about three miles above us. Our march to the rear continued on a by-road which brought us to the Warrenton branch of the O. & A. R. R. about three miles east of Warrenton. We rested here for a while and then after a march of about five miles further we halted for the night.
About 4 p. m. on the 13th we encountered the enemy's cavalry at Auburn creek. Our brigade held the advance of the column on this day, and the 57th was the leading regiment. Companies A and K acted as advance guard. These companies deployed on both sides of the road and opened fire on the rebels, who were dismounted and advancing through the woods and fields. Our firing soon brought up the rest of the brigade and a battery, whereupon, the rebels seeing we were well supported, mounted their horses and retreated at a lively gait. Several men of our regiment were slightly wounded in this affair. When the skirmish was over we resumed our march, and about dark we reached the English settlement called Greenwich, where we encamped, and our regiment was posted as pickets.