d added the Shenandoah
Valley to his field of operations.

From then on, Mosby was fighting a war on two fronts, dividing his
attention between the valley and the country to the east of Bull Run
Mountain, his men using their spare horses freely to keep the Union
rear on both sides in an uproar. The enemy, knowing the section from
whence Mosby was operating, resorted to frequent counter-raiding.
Often, returning from a raid, the Mosby men would find their home
territory invaded and would have to intercept or fight off the
invaders. At this time, Mosby was giving top priority to attacks on
Union transport whether on the roads or the railroads. Wagon trains
were in constant movement, both moving up the Shenandoah Valley and
bound for the Army of the Potomac, in front of Petersburg. To the east
was the Orange and Alexandria Railroad, to the south, across the end
of Mosby's Confederacy, was the Manassas Gap, and at the upper end of
the valley was the B. & O. The section of the Manassas Gap Railroad
along the southern boundary of Mosby's Confederacy came in for special
attention, and the Union Army finally gave it up for a bad job and
abandoned it. This writer's grandfather, Captain H. B. Piper, of the
Eleventh Pennsylvania Volunteer Infantry, did a stint of duty guarding
it, and until he died he spoke with respect of the abilities of John
S. Mosby and his raiders. Locomotives were knocked out with one or
another of Mosby's twelve-pounders. Track was torn up and bridges were
burned. Land-mines were planted. Trains were derailed and looted,
usually with sharp fighting.

By mid-July, Mosby had been promoted to lieutenant colonel and had a
total strength of around 300 men, divided into five companies. His
younger brother, William Mosby, had joined him and was acting as his
adjutant. He now had four guns, all twelve-pounders--two howitzers,
the Napoleon and a new rifle, presented to him by Jubal Early. He had
a compact, well-disciplined and powerful army-in-miniature. After the
Union defeat at Kernstown, Early moved back to the lower end of the
Shenandoah Valley, and McCausland went off on his raid in to
Pennsylvania, burning Chambersburg in retaliation for Hunter's
burnings at Lexington and Buchanan in Virginia. Following his
customary practice, Mosby made a crossing at another point and raided
into Maryland as far as Adamstown, skirmishing and picking up a few
prisoners and horses.

Early's invasion of Maryland, followed as