and McClellan's
armies are rapidly falling back, Sumner's corps covering the retreat, as
usual. We left the Court House at eight o'clock A. M., forming a line of
battle on Flint Hill. Heavy clouds of dust, from the rebel columns,
marching towards the Potomac, could be seen in the distance. Not being
attacked, our line of march was resumed; but shortly afterwards, a rebel
battery opened on our rear, directly from the town. General Sumner ordered
one section of our battery, and the First Minnesota infantry, to take
position, planting the two guns of the right section, one on each side of
the road. Shortly after dark the enemy appeared. We could hear the
unlimbering of the artillery. At that moment we opened lively with shell
and canister, while Colonel Sully threw his regiment across the road, and
kept up a brisk musketry fire on the advancing cavalry of the enemy. Being
unable to use their artillery, the rebels retreated instantly. Seven men
of the First Minnesota were killed and wounded. One of our limber-chests
was upset, the pole being broken by the horses, injuring John Setton,
driver, and one horse. Colonel Sully, anxious to fall back, advised
Captain Tompkins not to lose any time, and if needs be, to abandon the
gun. Captain Tompkins replied, he would carry the gun along or share the
fate of it. We all went to work, tying the two guns and limbers together
with ropes and straps. In the vicinity of Vienna, a body of cavalry made a
charge on our column, firing at us with pistols and carbines. The First
Maryland Cavalry, and Company I, First Minnesota, left us without offering
any resistance to them. The greatest excitement prevailed for some time.
General Sumner gave credit to our battery for not having left the guns.
Some said the charge was made by a party of our own cavalry by mistake;
but the dead and wounded, found in rebel uniform, contradicted that. After
a weary march, we arrived near Fort Ethan Allen, at three o'clock A. M.

_Wednesday, September 3._--Sumner's corps marched across the Chain Bridge
to Tenallytown, and went to camp.

_Thursday, September 4._--Tenallytown, Maryland. Heavy cannonade on the
upper Potomac.

_Friday, September 5._--Tenallytown. The rebel army has crossed the
Potomac. We left Tenallytown this morning. Marched to Rockville, twelve
miles from Washington, and went to camp three miles from that place. New
clothes were issued to-night.

_Saturday, September 6._--Near Rockville. This m