September 20, l862.
First Lieutenant Peter Haines,
Topographical Engineers, Commanding Battery M, Second United States Artillery.
SIR : I have the honor to make the following report of my section of your battery whilst detached by your order September 8, 1862.
I reported to Colonel Farnsworth, Eighth Illinois Cavalry, at Poolesville, Maryland. Immediately after reporting to Colonel Farnsworth, the enemy opened with one piece of artillery.
By order of Colonel Farnsworth, I went into an adjoining field and returned the enemyís fire. In a few minutes the enemy withdrew. I camped at Poolesville that night; the next morning went to Darnestown and engaged the enemy again. After firing a few rounds both parties ceased firing. That evening the remainder of the battery arrived and I returned to your command.
The next day, September 10, I was ordered to report to Captain Sanders, Sixth United States Cavalry; with him I went to Sugar Loaf Mountain and there engaged the enemy. After a short engagement I ceased firing and returned to your command by order of Captain Sanders.
The next day, September 11, I was ordered to report to Colonel McReynolds, First New York Cavalry. I went with him to the mouth of the Monocacy River and remained there until the next morning, when I went to Frederick City via Darnestown and Urbana.
September 13, with Colonel McReynolds, I went to Gettysburg Pennsylvania, via Mechanicstown and Smithsburg, where I arrived September 14.
September 15, I returned to Frederick City by the same route arriving at Frederick September 16.
September 17, I left Frederick and joined your command at Boonsborough on September 18 by order of General Pleasonton. September 19 on the road to Williamsport, Maryland, I was detached from you and went towards Williamsport with Major Adams, First New York Cavalry via Downsville, Maryland. When within one mile of Williamsport, met the enemy with four pieces of artillery, supported by cavalry. After half an hourís severe engagement and the loss of Private Doering,† Seventh New York, who was attached to my section and wounded, Major Adams withdrew his command to Downsville where we remained for the night. The next day, September 20, we proceeded to Williamsport and reported to Colonel Rush, Sixth Pennsylvania Cavalry who ordered me back to your command.
I am, Sir, very respectfully,
R. HUNTER CHAPIN,
First Lieutenant, Second United States Artillery.
Source: Janet Hewett, ed., The Supplement to the Official Records of the Union and Confederate Armies, 100 Volumes in 3 Parts, Wilmington (NC): Broadfoot Publishing Company, 1994-2001; Part 1, Vol. 3, pp. 522 - 523. From the Henry Jackson Hunt Papers, Library of Congress. Thanks to Jim Rosebrock for the transcription.