April 2, 1862 – Major General George B. McClellan landed on the Virginia Peninsula with a huge manpower advantage, even though he had fewer men than expected.
As April began, the Army of the Potomac continued being shuttled in continuous streams from Alexandria to Fort Monroe on the Peninsula between the York and James rivers. McClellan, still upset about being deprived of General Louis Blenker’s 10,000-man division, boarded the Commodore to head to the Peninsula and wrote his wife that he was “very glad to get away from that sink of iniquity (Washington).”
Before leaving, McClellan complied with orders and quickly submitted a roster to President Abraham Lincoln listing the troops he was leaving behind to defend Washington. While his corps commanders had proposed leaving 40,000, McClellan reported that he would be leaving 55,465: 35,476 in the Shenandoah Valley, 10,859 at Manassas Junction, 7,780 at Warrenton, and 1,350 along the lower Potomac.
Added to the 22,000 manning the Washington defenses, this totaled 77,465 men. However, McClellan transferred many units and double-counted them while in transit. He also relied on troops in the northern states to come down and man several garrisons, even though he had not directly ordered them to do so. In reality, McClellan left only about 30,000 men in the Washington and Manassas Junction area.
McClellan and his staff arrived at Fort Monroe on the 2nd. By this time, about 50,000 Federals, or more than half the Army of the Potomac, had landed on the Peninsula. This strip of land was roughly 50 miles long and 15 miles wide at its widest. McClellan’s army would have to march upon the Peninsula’s sandy ground, through dense woods, and across many waterways to get to the Confederate capital at Richmond, 70 miles away.
McClellan planned to quickly advance and establish a supply base at the head of the York near West Point. From there, he would fight the “decisive” battle between West Point and Richmond. His first obstacle would be Yorktown, a tobacco port where Lord Cornwallis surrendered to George Washington to end the War for Independence in 1781. Major General John B. Magruder defended Yorktown with his 15,000-man Army of the Peninsula.
McClellan intended to outflank Magruder with help from Federal gunboats. However, Flag Officer Louis M. Goldsborough, commanding the North Atlantic Blockading Squadron, informed McClellan that he could offer few gunboats because most of his fleet was busy defending against the Confederate ironclad C.S.S. Virginia. Naval officials later asserted that their artillery could not reach the Confederates on the high bluffs anyway.
Back at Washington, Brigadier General James S. Wadsworth, a former New York politician and current D.C. military governor, discovered the questionable math on McClellan’s roster of troops left behind. Acknowledging that a Confederate attack on the capital was “very improbable,” Wadsworth notified Secretary of War Edwin M. Stanton that only 19,000 soldiers were available to man the Washington defenses. This raised administration concern over whether McClellan had left the capital “entirely secure” as instructed.
Two of McClellan’s army corps remained in the Washington area, waiting to be transferred to the Peninsula–the I and II corps of Major Generals Irvin McDowell and Edwin V. Sumner respectively. Before leaving Alexandria, McClellan had directed Sumner to bring his corps to the Peninsula next, with McDowell’s to follow only after the rest of the army was approaching Richmond.
By this time, the Confederates in northern Virginia had fallen back to Fredericksburg and Orange Court House, and the Confederates in the Shenandoah Valley had withdrawn to Mount Jackson. Nevertheless, Stanton and Lincoln concluded that Washington needed more protection against an unlikely Confederate attack. Therefore, Stanton ordered McDowell’s 40,000-man I Corps, currently stationed near Manassas Junction, to stay behind. McDowell’s corps had originally been scheduled to go to the Peninsula first, but now it would not be going at all. This corps comprised about a third of McClellan’s army.
Lincoln issued an order through Adjutant General Lorenzo Thomas to McClellan: “The President, deeming the force to be left in front of Washington insufficient to insure its safety, has directed that McDowell’s army corps should be detached from the forces operating under your immediate direction.” Lincoln explained the order in a personal letter to McClellan: “I was satisfied with your arrangements to leave Banks at Manassas Junction, but when that arrangement was broken up (when Banks went to the Shenandoah Valley) and nothing was substituted for it of course I was not satisfied.”
To make things worse for McClellan, he was also informed that the 10,000-man Federal garrison at Fort Monroe would not be available for his use. This left McClellan with 60,000 fewer men than he expected to have on the Peninsula (Blenker’s 10,000, McDowell’s 40,000, and the 10,000 at Fort Monroe). However, he still had a tremendous advantage in manpower over Magruder’s small army at Yorktown. As such, Lincoln directed that “Gen. McClellan commence his forward movement from his new base at once.”
McClellan wrote his wife on April 3, not yet aware that McDowell was being held back, “I hope to get possession of Yorktown day after tomorrow.”
Bailey, Ronald H., Forward to Richmond: McClellan’s Peninsular Campaign (Alexandria, VA: Time-Life Books, 1983), p. 93; CivilWarDailyGazette.com (3 Apr 1862); Clark, Champ, Decoying the Yanks: Jackson’s Valley Campaign (Alexandria, VA: Time-Life Books, 1983), p. 71; Denney, Robert E., The Civil War Years: A Day-by-Day Chronicle (New York: Gramercy Books, 1992 [1998 edition]), p. 148; Donald, David Herbert, Lincoln (Simon & Schuster, Kindle Edition, 2011), Loc 7396; Fredriksen, John C., Civil War Almanac (New York: Checkmark Books, 2007), p. 130; Long, E.B. with Long, Barbara, The Civil War Day by Day (New York: Da Capo Press, Inc., 1971), p. 192