SIR: I have your letter asking me to give you a statement of the forces of General McDowell's army engaged in the battle of Bull Run, July 21, 1861.
Many of the men of that army were volunteers, called into service for three months by the President's proclamation of April 15, 1861. After they arrived in Washington, and were equipped, they were sent across the Potomac to General McDowell, and were hurriedly thrown into brigades and divisions, and then pushed into an active campaign, in order that they might do something before they were discharged. Even if the officers had understood army returns and the necessity for rendering them, they had not time to attend to such matters. It was not practicable at the time to ascertain the strength of the army with accuracy; and it is impossible now to make a return which can be pronounced absolutely correct.
The army of General McDowell in the campaign consisted of five divisions: Tyler's first division contained four brigades -- Keyes's, Schenck's, Sherman's, and Richardson's; Hunter's second division contained two brigades -- Andrew Porter's and Burnside's; Heintzelman's third division contained three brigades -- Franklin's, Willcox's, and Howard's; Runyon's fourth division was not organized into brigades; Miles's fifth division contained two brigades -- BIenker's and Davies's.
Miles's division, with Richardson's brigade of Tyler's division attached, was in reserve at and in front of Centreville. Some of it was lightly engaged on our side of Bull Run in repelling a feeble advance of the enemy.
Runyon's division was left to guard our communications with the Potomac, its advance being seven miles in rear of Centreville.
The abstract which appears on page 309, vol. ii., "Official Records of the Rebellion," and which you seem to regard as a return of McDowell's army at the battle of Bull Run, is not such, and was not prepared by me, but, as I understand, has been compiled since the war. It purports to give the strength of the "Department of North-eastern Virginia," July 16th and 17th, not of McDowell's army, July 21st.
In fact, it is not a return of General McDowell's army at the battle of Bull Run; and if used for calculating such a return, several facts should be borne in mind. First, it does not show the losses resulting from the discharge of the Fourth Pennsylvania Infantry and Varian's New York battery, which marched to the rear on the morning of the 21st, nor the heavy losses incident to the march of the army from the Potomac; second, it embraces two regiments -- the Twenty-first and Twenty-fifth New York Infantry which were not with the army in the field; and third, it contains the strength of Company E, Second United States Cavalry, as a special item, whereas that company is embraced in the strength of the second (Hunter's) division, to which it, with the rest of the cavalry, belonged.
In his report of the battle (p. 324, vol. ii., "Official Records of the Rebellion") General McDowell says he crossed Bull Run "with about eighteen thousand men." I collected information to that effect; for him at the time. His statement is substantially correct. The following is an exhibit in detail:
Total -- seven brigades
Griffin's Battery -- 4 ten-pounder rifle guns, 2 twelve-pounder howitzers.
Arnold's Battery -- 2 thirteen-pounder rifle guns, 2 six-pounder smooth-bore guns.
Rhode Island Battery -- 6 thirteen-pounder rfle guns.
Seventy-first New York Regiment's Battery -- 2 Dahlgren howitzers.
Total pieces. -- 24
Carlisle's Battery -- 2 thirteen-pounder rifle guns, 2 six-pounder smooth-bore guns.
Tidball's Battery -- 2 six-pounder smooth-bore guns, 2 twelve-pounder howitzers.
Greene's Battery -- 4 ten-pounder rifle guns.
Ayer's Battery -- 2 ten-pounder rifle guns, 2 six-pounder smooth bore guns, 2 twelve-pounder howitzers.
Edwards's Battery -- 2 twenty-pounder rifle guns, 1 thirty-pounder rifle gun.
James B. Fry,
Retired A. A. G. with rank of Colonel,
Brevet-Major General U. S. A.
New York, Oct. 1, 1884.