His first exploits had been so noised abroad that the young men from the neighboring counties and the soldiers at home on furloughs would request permission to join in his raids. He could easily muster fifty of these, known as "Mosby's Conglomerates," for any expedition. The opportunity for developing his ideas of border warfare was thus presented. With great vigor he renewed his attacks upon the Federal outposts. As a recognition of one of his successful exploits, the Confederate government sent him a captain's commission with authority to raise a company of partizan rangers. The material for this was already at hand, and on June 10, 1862, he organized his first company. This was the nucleus around which he subsequently shaped his ideal command. The fame of his achievements had already spread throughout Virginia and Maryland, and attracted to his standard many kindred spirits from both States. No conscripting was necessary. Those for whom this mode of warfare possessed a charm would brave hardship and danger for the privilege of enlisting under his banner. His recruits from Maryland, and many of those from Virginia, were compelled to pass through the Federal pickets in order to join his command. Yet great care had to be exercised in the selection of his men, and not every applicant was received. If an unworthy soldier procured admission, so soon as the mistake was discovered he was sent under guard as a conscript to the regular service.

Mosby reserved the right to select all of his officers, who were invariably chosen from those who had already demonstrated their fitness for this particular service. It has been said of a great military hero that the surest proof of his genius was his skill in finding out genius in others, and his promptness in calling it into action. Mosby, in his limited sphere, displayed a similar talent, and to this faculty, almost as much as any one thing, may be attributed his success with his enlarged command. When a sufficient number of men had enlisted to form a new company, he would have them drawn up in line and his adjutant would read to them the names of those selected for officers, with the announcement that all who were not in favor of their election could step out of the ranks and go to the regular service. Of course no one ever left. In order to comply with the law, the form of an election was then gone through with, and their commander's choice ratified. In no other body of troops were all the officers thus unanimously elected.

Mosby's command, as finally organized, consisted of eight companies of cavalry and one of mounted artillery, officered by a colonel, a lieutenant-colonel, and a major, with the usual complement of company officers. But the entire force was seldom combined. Instead of this, they would be divided into two or more detachments operating in different places. So it was not at all unusual for an attack to be made the same night upon Sheridan's line of transportation in the valley, upon the pickets guarding the Baltimore and Ohio Railroad, upon the outposts in Fairfax County, and upon the rear of the army manoeuvering against Lee. This explains—what at the time seemed to many of the readers of the Northern newspapers a mystery—how Mosby's men could be in so many different places at the same time. The safety and success of the Rangers were enhanced by these subdivisions, the Federals having become so alert as to make it extremely difficult for a large command either to evade their pickets or manoeuver within their lines. From fifty to one hundred men were all that were usually marched together, and many of their most brilliant successes were achieved with even a smaller force. Mosby had only twenty men with him when he captured Brigadier-General Edwin H. Stoughton. With these he penetrated the heart of the Federal camp, and carried off its commander. General Stoughton was in charge of an army of cavalry, infantry, and artillery, with headquarters at Fairfax Court-house. One dark night in March, 1863, Mosby, with this small detachment, evaded the Federal pickets, passed through the sleeping army, and with their camp-fires gleaming all around him, and their sentinels on duty, aroused their general from his slumbers, and took him captive with thirty-seven of his comrades.

But the novelty of Mosby's mode of warfare consisted chiefly in the manner of subsisting, quartering and protecting his men. The upper portion of Loudon and Fauquier counties, embracing a circuit of about thirty miles in diameter, was then known as "Mosby's Confederacy." By a glance at the map it will be observed that it bordered upon the Blue Ridge Mountains on the west, and the Bull Run Mountains on the east. The valley between is one of the richest, most beautiful, and highly cultivated in the State of Virginia. It was thickly inhabited with old Virginia families, who were loyal and true to the Southern cause. These people received Mosby's men into their houses as their guests, and neither danger nor want could tempt their betrayal. Robin Hood's band sought safety in the solitudes of Sherwood Forest, Marion's men secreted themselves "in the pleasant wilds of Snow's Island" and other South Carolina swamps, but the Partizan Rangers of Virginia protected themselves by dispersing in an open country among a sympathizing people. They never established a camp; to have done so would have invited capture. Each soldier had his boarding-house, where he lived when off duty, as a member of the family. From these they would come, singly or in groups, bringing their rations with them to some designated rendezvous, march rapidly to and from the point of attack, send their prisoners under guard to the nearest Confederate post, divide the spoil, and disperse. If they were pursued by an overwhelming force as was frequently the case, the evening found them scattered to the four winds, where each man, mounted upon his own fleet steed, could protect himself from capture. If the Federals attempted to follow the chase in small parties, the Rangers, from behind every hill and grove, would concentrate and dash upon them. If they marched in solid column, the Rangers would hang upon their flanks, firing upon them from behind trees, fences, and hilltops. In this way, General Julius Stahel, who had invaded Mosby's Confederacy with two brigades of cavalry and four pieces of artillery for the avowed purpose of utterly demolishing the Rangers, was so annoyed that he retired, thoroughly disgusted with an enemy "who only fought when they got their foe at a disadvantage."

As there were no civil officers commissioned by either party in all that section of Virginia, the people naturally turned to Mosby as their only representative of law and order. It was not unusual for them to submit their property controversies to him for decision. In this way he acquired a civil jurisdiction in connection with his military dictatorship. Being a lawyer by profession, educated at the University of Virginia, his civil administration became as remarkable for its prudence and justice as his military leadership was for magnanimity and dash. I heard an old citizen remark, "For two years Mosby was our ruler, and the country never was better governed." He protected the people from stragglers and deserters, who pillaged friend and foe alike. Every captured horse-thief was promptly executed. He required his own men to treat the citizens with fairness and courtesy, and any violation of this rule was punished by sending the offender to the regular service. Its observance was more easily enforced than would appear possible at first glance. The men were scarcely ever off duty, except for necessary rest. The officers were then distributed among them, and by their example and authority controlled, when necessary, the deportment of their men. The citizens with whom they lived also exercised a healthy influence over them. These relations engendered many attachments that ran like golden threads through the soldier's life and outlived the rough usages of war.

It thus became no easy matter to drive the Rangers from a territory so dear to them, and in which they were befriended by all. On two occasions the entire Federal army operating against General Lee passed through Mosby's Confederacy, and yet his men did not abandon it. They hid themselves in the mountains during the day, and descended upon the enemy at night. They thus observed every movement of the Federal army, and all valuable information was promptly sent to the Confederate general. On one of these occasions, June 17, 1863, Mosby found himself at ten o'clock at night between the infantry and cavalry commands of General Hooker's army. Observing three horses hitched near a house, with an orderly standing by, he left his command with the prisoners already captured, and taking with him three men, rode up to the orderly and was informed by him that the horses belonged to Major William E. Sterling and another officer. In a whisper he said to the orderly:

"My name is Mosby. Keep quiet!"

The man understood him to say that he (the orderly) was "Mosby," and very indignantly replied:

"No sir, I am as good a Union man as ever walked the earth."

"Those are just the sort I am after," said Mosby.