半岛会战

The Peninsula campaign (also known as the Peninsular campaign) of the American Civil War was a major Union operation launched in southeastern Virginia from March to July 1862, the first large-scale offensive in the Eastern Theater. The operation, commanded by Major General George B. McClellan, was an amphibious turning movement against the Confederate States Army in Northern Virginia, intended to capture the Confederate capital of Richmond. Despite the fact that Confederate spy Thomas Nelson Conrad had obtained documents describing McClellan's battle plans from a double agent in the War Department, McClellan was initially successful against the equally cautious General Joseph E. Johnston, but the emergence of the more aggressive General Robert E. Lee turned the subsequent Seven Days Battles into a humiliating Union defeat.

McClellan landed his army at Fort Monroe and moved northwest, up the Virginia Peninsula. Confederate Brigadier General John B. Magruder's defensive position on the Warwick Line caught McClellan by surprise. His hopes for a quick advance foiled, McClellan ordered his army to prepare for a siege of Yorktown. Just before the siege preparations had been completed, the Confederates, now under the direct command of Johnston, began a withdrawal toward Richmond. The first heavy fighting of the campaign occurred during the Battle of Williamsburg in which the Union troops managed some tactical victories, but the Confederates continued their withdrawal. An amphibious flanking movement to Eltham's Landing was ineffective in cutting off the Confederate retreat. During the Battle of Drewry's Bluff, an attempt by the US Navy to reach Richmond by way of the James River was repulsed.

Background

Military situation

On August 20, 1861, Maj. Gen. George B. McClellan formed the Army of the Potomac, with himself as its first commander. During the summer and fall, McClellan brought a high degree of organization to his new army, and greatly improved its morale by his frequent trips to review and encourage his units. It was a remarkable achievement, in which he came to personify the Army of the Potomac and reaped the adulation of his men.……

Opposing forces

Union

The Army of the Potomac had approximately 50,000 men at Fort Monroe when McClellan arrived in late March, but this number grew to 121,500 before hostilities began. The army was organized into three corps and other units, as follows:

II Corps, Brig. Gen. Edwin V. Sumner commanding: divisions of Brig. Gens. Israel B. Richardson and John Sedgwick

III Corps, Brig. Gen. Samuel P. Heintzelman commanding: divisions of Brig. Gens.……

Initial movements

Movement to the Peninsula and the siege of Yorktown

McClellan's army began to sail from Alexandria on March 17. It was an armada that dwarfed all previous American expeditions, transporting 121,500 men, 44 artillery batteries, 1,150 wagons, over 15,000 horses, and tons of equipment and supplies. An English observer remarked that it was the "stride of a giant."

With the Virginia still in operation, the U.S.……

Battles

Williamsburg

By May 5, Johnston's army was making slow progress on muddy roads and Stoneman's cavalry was skirmishing with Brig. Gen. J.E.B. Stuart's cavalry, Johnston's rearguard. To give time for the bulk of his army to get free, Johnston detached part of his force to make a stand at a large earthen fortification, Fort Magruder, straddling the Williamsburg Road (from Yorktown), constructed earlier by Magruder.……

The Seven Days Battles

Despite claiming victory at Seven Pines, McClellan was shaken by the experience. He redeployed all of his army except for the V Corps south of the river, and although he continued to plan for a siege and the capture of Richmond, he lost the strategic initiative and never regained it.

Lee used the month-long pause in McClellan's advance to fortify the defenses of Richmond and extend them south to the James River at Chaffin's Bluff.……