The year 1862 began well for the armies charged with defending the Union. In January, a victory at Mill Springs in Kentucky chased a Confederate army out of that critical border state. Brig. Gen. Ulysses S. Grant’s capture of Forts Henry and Donelson in February secured western Tennessee for his army to operate. A Union victory at Pea Ridge in early March removed another Rebel army from the troublesome border state of Missouri. Yet for all the successes west of the Appalachians, the politicians and newspapers in the east still demanded that the army there, the new Army of the Potomac, move “on to Richmond” and capture the Confederate capital.
The army commander, 34-year old Maj. Gen. George B. McClellan, made plans to do so. The previous August, McClellan inherited a broken, demoralized army, and, within a few months, had completely reorganized and reequipped it. Brilliant at those skills, “Little Mac” was idolized by his men and morale was high. Volunteer regiments poured into Washington DC, and although the first winter took a heavy toll in deaths from disease in the camps, by March McClellan had nearly 120,000 men ready to move.
Still facing the Confederate army of Gen. Joseph Johnston entrenched around Manassas, McClellan sought to avoid another head-on push toward Bull Run that might echo last July’s debacle. Instead, McClellan looked to the Potomac River as an avenue of advance. He planned to embark his army on transports and land at Urbanna, Virginia, 100 miles downstream from Washington DC on the lower Rappahannock River, outflanking Johnston, and from there march overland to Richmond. Before McClellan could move, Johnston evacuated his works at Manassas and moved south of the Rappahannock, negating McClellan’s strategy. Undaunted, McClellan revised his plans. He would bypass the Rappahannock and move down the entire length of the Potomac to Hampton Roads, landing his troops at Fort Monroe on the tip of the peninsula between the York and James Rivers. From there, using the fort as a base, McClellan could move up the peninsula toward Richmond.
Fortunately for the Union, the massive Fort Monroe, the largest masonry fort in the country, was a valuable toehold in southeastern Virginia, partially making up for the loss of the U. S. Navy docking facilities across the roadstead in Portsmouth. Unfortunately for the Union, the Confederates had rebuilt the scuttled seam frigate USS Merrimack there and turned her into an ironclad ram renamed the CSS Virginia. On March 8, the Virginia engaged the wooden ships of the Federal blockading fleet at Hampton Roads and destroyed two warships. That evening, the new turreted ironclad USS Monitor arrived from New York to protect the fleet. The next day, the battle between Monitor and Virginia at the mouth of the James River revolutionized naval warfare forever. Although the battle was a draw, Virginia was forced to seek shelter near Portsmouth, and no longer posed a threat to Federal ships supporting the advance of McClellan’s army while the Monitor remained in the area.
With Virginia neutralized, McClellan's army sailed from Alexandria on March 17 with 121,000 men, 44 artillery batteries, 1,150 wagons, over 15,000 horses, and tons of equipment. Advancing from Fort Monroe the first week of April, McClellan’s army first met the Confederates on April 5 at Lee’s Mill along the Warwick River. Thwarted in his attempt to outflank the Rebels in the small battle there, and again at Dam No. 1 on April 16, McClellan decided to lay siege across the neck of the peninsula. His lines extended to the old Revolutionary War battlefield at Yorktown, where he brought up his heavy siege artillery and settled in. Reconnaissance balloons floated skyward behind Union lines and reported distant Confederate movements. Before he could execute a planned infantry attack on May 4, the Confederates, now under Johnston’s overall command, slipped away toward Williamsburg. McClellan followed, and bloody fighting took place there on May 5 with nearly 4,000 casualties and over 70,000 men engaged.
McClellan’s progress up the peninsula was slow but steady as Johnston pulled back. On May 7, McClellan attempted an amphibious landing on the York River behind Johnston’s left, but was beaten back at Eltham’s Landing. Behind Johnston’s right, a navy force including the USS Monitor attempted to pass the Confederate batteries at Drewry’s Bluff on the James River, but were turned around on May 15. The Monitor and other ships were free to flank McClellan’s army on both rivers since Norfolk and Portsmouth had been captured by the Federals on May 10, and the Virginia was scuttled the next day.
At the outskirts of Richmond, just seven miles east of the city, Johnston halted his retreat and attacked McClellan’s army as it straddled the Chickahominy River. The Battle of Seven Pines on May 31 was one of the most consequential of the war. During the fight, Johnston was wounded, and command of his army given to Gen. Robert E. Lee. Lee had been defeated by McClellan in a small battle in western Virginia the previous year, and served as Jefferson Davis’ military advisor. Now with an army at his command, however, Lee soon proved his offensive capabilities.
In the last week of June, Lee launched an aggressive campaign against McClellan. Over the course of seven days beginning June 26, Lee attacked the Union army at Beaver Dam Creek near Mechanicsville, at Gaines’ Mill along Boatswain’s Creek, at a road junction near Glendale, and finally on the north slope of Malvern Hill. In the near-constant heavy fighting, Lee found a winning pair of division commanders in Maj. Gens. James Longstreet, Johnston’s trusted subordinate; and Thomas J. “Stonewall” Jackson, recalled from the Shenandoah Valley. McClellan’s army, defeated or withdrawn at every battle, finally pulled back to the James River at Harrison’s Landing. His campaign against Richmond was over.
On July 2, Lee watched the Union army crawl back to the banks of the James far below Richmond. In command of the Army of Northern Virginia for just 30 days, Lee had defended the Confederate capital from the first major Union offensive campaign in the east. Lee’s offensive ushered in an era of Southern dominance in the east.