Potomac; others that McCausland, with a like column, was marching to join Johnson; others, again represented Early and Breckinridge behind the Catoctin Mountain, with 30,000 men, moving upon Frederick City. In short, the most reliable intelligence was of a character that reduced the defense of that town to a secondary consideration. If the enemy's force was correctly reported, his designs were upon Washington or Baltimore. In the hope of evolving something definite out of the confusion of news, I went in person to Frederick City, leaving my inspector-general, Lieutenant-Colonel Catlin, at the railroad bridge, to stop such of the veteran regiments as arrived there. The Eleventh Maryland remained with him. My purpose was to conduct a reconnaissance over the mountain, to brush aside, if possible, the curtain that seemed to overhang it. In the midst of preparation for this movement, a telegram from Major-General Sigel reached me, stating that the enemy had that morning retired from before Maryland Heights, and was marching with his main body up the Middletown Valley toward Boonsborough. The question then was, Were the rebels marching for Pennsylvania or coming eastward by the Jefferson or Middletown pikes? I concluded delayed.
As Johnson still held the mountain pass to Middletown, the day (8th) was spent in trying to draw him into the valley with such re-enforcements as he might have received. A feigned retreat from the town was but partially successful; he came down, but, under fire of Alexander's guns, galloped back again. About 6 o'clock in the afternoon Colonel Catlin telegraphed me that a heavy force of rebel infantry was moving toward Urbana by the Buckeystown road. This threatened my lines of retreat and the position at Monocacy bridge. What was more serious, it seemed to disclose a purpose to obtain the pike to Washington, important to the enemy for several causes, but especially so if his designs embraced that city, then in no condition, as I understood it, to resist an army like that attributed to Early by General Sigel. I claim no credit for understanding my duty in such a situation; it was self-apparent. There was no force that could be thrown in time between the captain and the rebels but mine, which was probably too small to defeat them, but certainly strong enough to gain time and complete them to expose their strength. If they were weak, by going back to the bridge I could keep open the communication with General Sigel; on the other hand, if they were ever so strong it was not possible to drive me from that position, except by turning one my flanks; if my right, retreat was open by the Washington pike; if my left, the retirement could be the pike to Baltimore. I made up my mind to fight, and accordingly telegraphed General Halleck:
I shall withdraw immediately from Frederick City, and put myself in position to cover road to Washington, if necessary.
This was done by marching in the night to the railroad bridge, where Brigadier-General Ricketts was in waiting. I had then the following regiments of his division:
First Brigade, Colonel W. S. Truex commanding, 1,750 strong-One hundred and sixth New York, Captain Paine commanding; One hundred and fifty-first New York, Colonel Emerson; Fourteenth New Jersey, Lieutenant-Colonel Hall; Tenth Vermont, Colonel Henry; Eighty-seventh Pennsylvania, Lieutenant-Colonel Stahle.