Our cavalry had quite a battle with the enemy at Brandy Station, which ended favorably for us, and also made it obvious that the rebels were moving northward, thus taking the initiative in what became known as the "Gettysburg Campaign." On June 11th, about noon, we were ordered to strike tents, and were soon on the march, over the hills, and through the ravines of Stafford county, which were no longer to be used by us as camping grounds. The day was very warm and there was considerable straggling, but the men all got up by night, when we camped at Hartwood church. On the 12th we marched to near Bealeton station, on the old Orange & Alexandria railroad, where we halted for the night, and next day marched for a few miles toward Rappanhannock station. On the 14th we started in the evening and marched northward to Catlett station, where we arrived about midnight. On the 15th we moved to Manassas Junction. This was one of the hottest days of the season, and some forty men of our division were prostrated by sunstroke. On the 16th, which was another hot and dusty day, we marched to Bull Run and encamped at Mitchell's ford. On the 17th we continued our march to Centerville, where we remained until the evening of the 19th, when we started for Gum Springs. After we had gone about two miles a violent storm of rain set in. This was one of the worst night marches we ever made. The night was dark as pitch, only an occasional flash of lightning to show us the way. When we halted for the night we were drenched to the skin and as our matches were all damp we had hard work to start our campfires. When we had got our fires started we found that the regiment must move a mile further on to go on picket. This was very discomforting, but it had to be done, for such is the life of a soldier. In the meantime the enemy had been moving northward on the west side of the Blue Ridge mountains. A Union force under General Milroy of about seven thousand men was attacked by the rebel General Ewell, who captured many of them and drove the rest across the Potomac. This occurred on the 13th and 14th of June. On June 25th, the 57th with the rest of the 3d corps moved from Gum Springs and crossed the Potomac at Edwards ferry into Maryland and moved up the river to the mouth of the Monocacy river. The corps of Hill and Longstreet of Lee's army crossed the Potomac at Williamsport and Sheppardstown and moved toward Pennsylvania. They were preceded for several days by Ewell, who was now in that state and threatening Harrisburg.