The method of operation involved executing small raids with up to 150 men (but usually 20 to 80) behind Union lines by entering the objective area undetected, quickly executing their mission, and then rapidly withdrawing, dispersing the troops among local Southern sympathizers, and melting into the countryside.

Mosby's area of operations was Northern Virginia from the Shenandoah Valley to the west, along the Potomac River to Alexandria to the east, bounded on the south by the Rappahannock River, with most of his operations centered in or near Fauquier and Loudoun counties, in an area known as "Mosby's Confederacy".
Mosby's command operated mainly within the distance a horse could travel in a day's hard riding, approximately 25 miles (40 km) in any direction from Middleburg, Virginia.
They also performed raids in Maryland.

Of his purpose in raiding behind the Union lines, Mosby said:
My purpose was to weaken the armies invading Virginia, by harassing their rear... to destroy supply trains, to break up the means of conveying intelligence, and thus isolating an army from its base, as well as its different corps from each other, to confuse their plans by capturing their dispatches, are the objects of partisan war.
It is just as legitimate to fight an enemy in the rear as in the front.
The only difference is in the danger ...
— Col.
John S. Mosby, CSA
Mosby felt that "a small force moving with celerity and threatening many points on a line can neutralize a hundred times its own number.
The line must be stronger at every point than the attacking force, else it is broken."

According to the memoirs of former partisan Munson, Mosby welcomed volunteers attracted by the glory of the fight and the allure of booty, and had an eye for intelligence, valor, resourcefulness, but "what Mosby liked best was youth.
He agreed with Napoleon, that boys make the best soldiers . . .
mere boys, unmarried and hence without fear or anxiety for wives or children."
A few partisans were wizened old men in their 40s, but most were in their late teens or early 20s; two paroled after the war at Winchester were only 14 years old.
An adolescent boy released from school for the day in Upperville just as Mosby's men were chasing Union troopers out of town "became so excited that he mounted a pony and joined in the chase with no weapon except his textbook.
This would be the last day of study for Henry Cable Maddux . . .
but the first of many raids with Mosby's men."
The method of operation involved executing small raids with up to 150 men (but usually 20 to 80) behind Union lines by entering the objective area undetected, quickly executing their mission, and then rapidly withdrawing, dispersing the troops among local Southern sympathizers, and melting into the countryside.
Mosby's area of operations was Northern Virginia from the Shenandoah Valley to the west, along the Potomac River to Alexandria to the east, bounded on the south by the Rappahannock River, with most of his operations centered in or near Fauquier and Loudoun counties, in an area known as "Mosby's Confederacy". Mosby's command operated mainly within the distance a horse could travel in a day's hard riding, approximately 25 miles (40 km) in any direction from Middleburg, Virginia. They also performed raids in Maryland.
Of his purpose in raiding behind the Union lines, Mosby said:
My purpose was to weaken the armies invading Virginia, by harassing their rear... to destroy supply trains, to break up the means of conveying intelligence, and thus isolating an army from its base, as well as its different corps from each other, to confuse their plans by capturing their dispatches, are the objects of partisan war. It is just as legitimate to fight an enemy in the rear as in the front. The only difference is in the danger ...
— Col. John S. Mosby, CSA
Mosby felt that "a small force moving with celerity and threatening many points on a line can neutralize a hundred times its own number. The line must be stronger at every point than the attacking force, else it is broken."
According to the memoirs of former partisan Munson, Mosby welcomed volunteers attracted by the glory of the fight and the allure of booty, and had an eye for intelligence, valor, resourcefulness, but "what Mosby liked best was youth. He agreed with Napoleon, that boys make the best soldiers . . . mere boys, unmarried and hence without fear or anxiety for wives or children." A few partisans were wizened old men in their 40s, but most were in their late teens or early 20s; two paroled after the war at Winchester were only 14 years old. An adolescent boy released from school for the day in Upperville just as Mosby's men were chasing Union troopers out of town "became so excited that he mounted a pony and joined in the chase with no weapon except his textbook. This would be the last day of study for Henry Cable Maddux . . . but the first of many raids with Mosby's men."
43rd Battalion, Virginia Cavalry