perceiving that his line of communication was held by the enemy, and that his force was weakened by the absence of the Twenty-third Illinois Regiment, he determined to evacuate Petersburg and fall back on New Creek, according to precautionary orders, already received. He accordingly withdrew his forces at midnight, and carrying with him all stores and Government property he retired by was of Greenland Gap, and arrived at New Creek safe and in good condition on the 1st of February.

At daylight on the 31st, the enemy opened fire on the abandoned works at Petersburg, and shelled them for some time before he discovered that they were unoccupied. Perceiving at length that the garrison had escaped, he hastened by the direct route to Greenland Gap, hoping to cut off Colonel Thoburn's retreat, but he arrived too late.

The enemy still continued to press upon Colonel Mulligan's outposts, both in the New Creek and Patterson's Creek Valleys, showing a considerable force of all arms on both points. I began to apprehend that his ultimate designs were to effect the destruction of the Baltimore and Ohio Railroad, and that at the same time he might attack the post at New Creek, or even hazard a coup de main upon Cumberland with a view to plunder. I therefore held Mulligan's division, strengthened by Thoburn, ready for defensive or offensive operations, as circumstances might dictate, and sent an order after the mounted column at Wardensville to move as speedily as possible upon Romney, at which point this force would have an opportunity to strike the enemy in flank and rear, and would be able to communicate more directly with Colonel Mulligan. In the mean time two regiments of infantry, Twelfth [West] Virginia and Thirty-fourth Massachusetts, arrived by rail from Harper's Ferry, and with one light battery were held to secure Cumberland against any sudden movements.

On the morning of February 2, hearing from Colonel Mulligan that the enemy were retiring, I ordered him to follow at once, and notified him that four regiments of our mounted troops would arrive at Romney that night to co-operate with him. Suddenly, about noon on the same day (2nd), the enemy, about 500 strong, under Rosser, made his appearance at Patterson's Creek Station, capturing a portion of the company of infantry guarding the road killing and wounding several and setting fire to Patterson's Creek bridge and also to North Branch bridge, 2 miles from the former and 6 miles from Cumberland.

I immediately took command of the forces at this place, and marched toward the menaced point, but presently ascertained that the enemy was hastily retiring by the way he came, having failed to do any serious damage to the road. Rosser retired by way of Sheets' Mill, where two regiments of infantry were stationed to support him. It being impossible to pursue with the infantry under my immediate command, I now depended on the mounted troop I had set in motion to intercept and punish the enemy's temerity.

Lieutenant-Colonel Fitz Simmons, commanding the mounted column from the valley of the Shenandoah, received the order directing him to move on Romney while at Wardensville, and responded with commendable promptness, arriving at the time expected. Unfortunately he here received information that the enemy was destroying the railroad in the neighborhood of Green Spring. Leaving a detachment to hold Romney, he followed this false scout to Springfield,