The right wing of the Federal army, from Falmouth to Bull Run Mountain, was covered by Averell's division of cavalry, composed of McIntosh's and Duffieas brigades and two small regular regiments, the First and Fifth, forming a brigade under Captain Reno.
After assembling them secretly, Averell took up the line of march on the 16th at the head of his three brigades, numbering between two thousand and twenty-five hundred horses, with a battery of artillery.
The following morning, March 17, th as skirmishers, which, notwithstanding Stuart's efforts, is instantly driven back in disorder and out of the clearing by the well-sustained fire of the Federals.
The latter have deployed themselves, McIntosh on the right, Duffie on the left, and Reno in the centre, with the Fifth Cavalry, while the First is kept in reserve.
The battle soon rages along the line, the Confederates assuming at first the offensive, with the more vigor that they are not aware of the number of their adversaries.