After the fight at Trevillian’s, then, he gave Johnson orders to prepare for the trip. The best horses in the cavalry command were selected, and the best men in the battalion picked out, but whilst shoeing his horses and recruiting his men in Goochland county, he was prevented from carrying out his much cherished plans by an order from General Early to join him at once with his battalion in the Valley, and cover his rear whilst that General went after Hunter, who had marched upon Lynchburg. In a week Early returned to Staunton, and it was then that Colonel Johnson received his long delayed commission as Brigadier General of cavalry, and was at once assigned to the command of the brigade formerly commanded by W. E. Jones, who had been killed at the battle fought near New Hope. Much to his gratification he was given permission, on the 3d day of July, to attach the First Maryland to his brigade, and then ordered to take the advance of Early’s army, moving on Martinsburg. At Leetown the brigade encountered Mulligan’s advance, and after a severe fight the enemy was driven back with loss. In this affair the First Maryland fought with its accustomed vim. On the 5th of July General Johnson crossed the Potomac at Sharpsburg, where he met a small force of the enemy’s cavalry, which Lieutenant George M. E. Shearer, with a detachment of the First Maryland, pursued into Hagerstown, where coming suddenly upon a superior force he was compelled to retreat upon the main body. In the pursuit which ensued Shearer was taken prisoner, along with several of his men. General Johnson now shaped his course in the direction of Frederick, in the vicinity of which he awaited the arrival of Early, who overtook him on the 8th. On the 9th, General Early dispatched General Johnson on a secret service by special order from General Lee. In this order he was directed to destroy communication between Baltimore and the North, threaten Baltimore, and break the railroad and cut the telegraph wires between Baltimore and Washington, and thence move on Point Lookout so as to attack on the morning of the 12th, when an attack was also to be made on the sea side. After releasing the prisoners, some fifteen thousand, he was to take command of them and rejoin Early at Bladensburg, whilst that General was in the meantime to attack Washington and carry it by assault.