Horace Greeley, The American Conflict: A History of the Great Rebellion in the United States of America, 1860-65: its Causes, Incidents, and Results: Intended to exhibit especially its moral and political phases with the drift and progress of American opinion respecting human slavery from 1776 to the close of the War for the Union. Volume II.

[129] averaged about 220,000 men,¹ was at no time large enough, according to his computation, to justify a determined offensive, since he persisted in computing the Rebel army confronting him at no less than “1500,000 strong, well drilled and equipped, ably commanded and strongly intrenched.” ²

Now, the movement first contemplated, by way of the Rappahannock and Urbana — still more, that ultimately decided on by way of Fortress Monroe and the Peninsula — involved a division of his army, and the reservation of a considerable part of it for the protection of Washington, as also the securing of Maryland and the Baltimore and Ohio Railroad from desolating raids down the Shenandoah Valley. President Lincoln had reluctantly given his assent to this circumnlittoral advance, on these expressed conditions:

Executive Mansion, Washington, March 8, 1862.
President's General War order, No. 3:

Ordered, That no change of the base of operations of the Army of the Potomac shall be made without leaving in and about Washington such a force as, in the opinion of the General-in-Chief and the commanders of army corps, shall leave said city entirely secure.

That no more than two army corps (about 50,000 troops) of said Army of the Potomac shall be moved en route for a new base of operations until the navigation of the Potomac, from Washington to the Chesapeako Bay, shall be freed from the enemy's batteries, and other obstructions, or until the President shall hereafter give express permission.

That any movement as aforesaid, en route for a new base of operations, which may be ordered by the General-in-Chief, and which may be intended to move upon the Chesapeake Bay, shall begin to move upon the bay as early as the 18th of March instant; and the General-in-Chief shall be responsible that it so moves as early as that day.

Ordered, That the army and navy co-operate in an immediate effort to capture the enemy's batteries upon the Potomac between Washington and the Chesapeake Bay.

Abraham Lincoln. L. Thomas, Adjutant-General.

Gen. McClellan's chief of spies had by this time reduced the force of the Rebels in Northern Virginia³ to 115,500 men, with 300 field and 26 to 30 siege-guns — quite a formidable army, if its leader should conclude, after Gen. McClellan's embarking the bulk of his forces for Fortress Monroe, to make a rush upon Washington from behind the Rappahannock. Five days later, Secretary Stanton wrote, as we have already seen, to Gen. McClellan, that the President made o objection to his plan of operations, provided he would--

1st. Leave such force at Manassas Junction as shall make it entirely certain that the enemy shall not repossess himself of that position and line of communication.

2d. Leave Washington entirely secure.

3d. Move the remainder of the force down the Potomac — choosing a new base at Fortress Monroe, or anywhere between here and there; or, at all events, move such remainder of the army at once in pursuit of the enemy by some route.

Just before starting for the Peninsula, Gen. McClellan received, “with surprise,” the following note, involving a subtraction, he estimates, of 10,000 troops from the force which he expected to have transferred to the Peninsula:

Executive Mansion, Washington, March 31, 1862.
Major-General McClellan:

Mr dear Sir: This morning I felt constrained to order Blenker's division to Fremont; and I write this to assure you that I did so with great pain, understanding that you would wish it otherwise. If you could know the full pressure of the case, I am confident that you would justify it, even