John G. Nicolay, The Outbreak of Rebellion

[163] from July 1st to the 13th, informed Patterson that McDowell would make an advance against Beauregard, and that Johnston must be defeated or detained in the Shenandoah Valley, in order that their two armies might not unite and defeat McDowell. “I telegraphed to you yesterday,” was Scott's language, “if not strong enough to beat the enemy early next week, make demonstrations so as to detain him in the valley of Winchester; but if he retreats in force toward Manassas, and it be too hazardous to follow him, then consider the route via Key's Ferry, Leesburg, etc.” That Patterson correctly understood the order is shown by his reply: “I have thus far succeeded in keeping in this vicinity the command under General Johnston, who is now pretending to be engaged in fortifying at Winchester, but prepared to retire beyond striking distance if I should advance too far. To-morrow I advance to Bunker Hill preparatory to the other movement. If an opportunity offers, I shall attack; but, unless I can rout, shall be careful not to set him in full retreat upon Strasburg.”

But the wishes of the Administration and General Scott were not allowed to depend alone on the customary orders. Patterson's former indecision and hesitancy had created a doubt of his disposition to fight; and a similar hesitancy was once more manifesting itself in his complaints, requests, and especially in his growing exaggeration of his antagonist's strength. It is always deemed hazardous to change commanders on the eve of battle, and therefore the alternative was adopted of sending General Sandford to him with additional reinforcements; who, waiving his rank, should take command under Patterson, and prompt him in pushing forward the army. Sandford, accepting the duty, reported to Patterson with four regiments from Washington, about July 10th; the column under General Stone also