he Army of the Potomac, Heintzelman's and Porter's corps
were already with Pope, Franklin's was at Alexandria, and Sumner's
was beginning to arrive. As soon as it was known at the War
Department that McClellan was present, General Halleck's
correspondence was of course with him, and we passed under his
orders. [Footnote: Official Records, vol. xii. pt. iii. pp. 688,
689, 691.] It had already been learned that 'Stonewall' Jackson was
with infantry as well as cavalry at Manassas, and that the Bull Run
bridge had been burned, our troops being driven back three or four
miles from it. McClellan thought it necessary to organize the two
corps at Alexandria and such other troops as were there, including
mine, first to cover that place and Washington in the possible
contingency that Lee's whole army had interposed between General
Pope and the capital, and, second, to open communication with Pope
as soon as the situation of the latter could be learned. Couch's
division was still at Yorktown, and orders had been issued by
Halleck to ship 5000 new troops there to relieve Couch and allow his
veteran division to join the Potomac Army. [Footnote: _Id_., p.
689.]

McClellan directed me to take the two regiments with me into camp
with Franklin's corps at Annandale, three miles in front of
Alexandria, and to obey Franklin's orders if any emergency should
occur. [Footnote: _Id_., p. 692.] I found, at the
post-quartermaster's office, an officer who had served in West
Virginia a year before, and by his hearty and efficient good-will
secured some supplies for the regiments with me during the days that
were yet to pass before we got our own trains and could feel that we
had an assured means of living and moving in an independent way. We
bivouacked by the roadside without shelter of any sort, enveloped in
dense clouds of dust from the marching columns of the Army of the
Potomac, their artillery and wagons, as they passed and went into
camp just in front of us. About noon, on Thursday (28th), Colonel
Scammon joined me with the two regiments he had taken toward
Manassas, and we learned the particulars of the sharp engagement he
had at the railway bridge.

The train carrying the troops approached the bridge over Bull Run
about eight o'clock in the morning on Wednesday, and Colonel Scammon
immediately pushed forward the Twelfth Ohio (Colonel White) to the
bridge itself and the bank of the stream. He met the New Jersey
brigade of four regiments