His letters to his wife told of his early military experiences--his pleasure at receiving one of the fine new Sharps carbines which Captain Jones had wangled for his company, and, later, a Colt .44 revolver: his first taste of fire in the Shenandoah Valley, where the company, now incorporated into Colonel Stuart's First Virginia Cavalry, were covering Johnston's march to re-enforce Beauregard: his rather passive participation in the big battle at Manassas. He was keenly disappointed at being held in reserve throughout the fighting. Long afterward, it was to be his expressed opinion that the Confederacy had lost the war by failing to follow the initial victory and exploit the rout of McDowell's army. The remainder of 1861 saw him doing picket duty in Fairfax County. When Stuart was promoted to brigadier general, and Captain Jones took his place as colonel of the First Virginia, Mosby became the latter's adjutant. There should have been a commission along with this post, but this seems to have been snarled in red tape at Richmond and never came through. It was about this time that Mosby first came to Stuart's personal attention. Mosby spent a night at headquarters after escorting a couple of young ladies who had been living outside the Confederate lines and were anxious to reach relatives living farther south. Stuart had been quite favorably impressed with Mosby, and when, some time later, the latter lost his place as adjutant of the First by reason of Jones' promotion to brigadier general and Fitzhugh Lee's taking over the regiment, Mosby became one of Stuart's headquarters scouts. Scouting for Jeb Stuart was not the easiest work in the world, nor the safest, but Mosby appears to have enjoyed it, and certainly made good at it. It was he who scouted the route for Stuart's celebrated "Ride Around MacClellan" in June, 1862, an exploit which brought his name to the favorable attention of General Lee. By this time, still without commission, he was accepted at Stuart's headquarters as a sort of courtesy officer, and generally addressed as "Captain" Mosby. Stuart made several efforts to get him commissioned, but War Department red tape seems to have blocked all of them. By this time, too, Mosby had become convinced of the utter worthlessness of the saber as a cavalryman's weapon, and for his own armament adopted a pair of Colts.