On August 29th 1862 the regiment, in command of Lieutenant Colonel Dillman, Colonel Poe being in command of the Brigade, continued the march, crossed Bull Run, on the Extreme Right, moving to the front, deployed as skirmishers, and on re-crossing Bull Run soon discovered the Confederates in force, where he opened a heavy fire with shell and shrapnel from a number of batteries, soon the Regiment was withdrawn across the stream under a heavy fire from the batteries.

On the 30th, again deployed as skirmishers, moving down the stream by the right flank, re-crossing, it withdrew from the field, being engaged in protecting the flank and rear of the Brigade from the numerous assaults of the Confederate cavalry, and although several furious charges were made, they were gallantly repulsed, then the march resumed, reaching centerville about 11 p.m.