President Lincoln and Gen. George McClellan in McClellan's tent at Antietam, Md. (Library of Congress Prints and Photographs Division)

In May 1862, the one-year-old Confederacy appeared to be on the brink of collapse. The Union had produced a string of victories from the coast of North Carolina to the far West, and a massive Federal army had just reached the outskirts of Richmond, the rebel capital, ready to destroy the nerve center of the rebellion.

Since the fall, the Confederates had lost some 40,000 men, double that of their Union counterparts. The Confederacy, with less than half the population of the North, could ill afford to take such losses.

Then the tables turned.

By the end of August, the Confederates were in central Kentucky driving hard for Louisville. In the East, not only had the Federal army been thrown back from Richmond, but it also had been driven all the way to the Washington defenses.

Who or what was responsible for such a startling reversal?

Besides the brilliant maneuvering of Confederate Gens. Robert E. Lee and Thomas “Stonewall” Jackson, conventional wisdom has pinned the blame mainly on Gen. George B. McClellan, who led the Union offensive on Richmond.

His over-cautious approach, the story goes, kept him bottled up at Yorktown for a month conducting siege warfare on a rebel army one-fifth the size of his. He vastly overestimated the strength of the enemy and made irrational calls for reinforcements. When the rebels finally retreated to Richmond, he did not pursue quickly enough. After Jackson joined Lee in Richmond and drove back the Union soldiers, McClellan withheld reinforcements from Gen. John Pope for petty political reasons, contributing to his army’s defeat.

But there is another way to look at the spring and summer of 1862, and in this version, the strategic mistakes are Lincoln’s.

In early March, McClellan told the president of his plan to capture Richmond. His offensive force would steam down the Chesapeake Bay to the peninsula between the York and James rivers and assault the rebel capital. His defensive force would man the forts surrounding Washington and guard the two main approaches from the south — the Piedmont and the head of the Shenandoah Valley. At the start of the campaign, McClellan had almost 190,000 men at his disposal.

How much of McClellan’s army should be allocated to defense became a serious point of contention with Lincoln, who was fixated on Washington’s security. McClellan’s lieutenants recommended 55,000 men, leaving the main assault force with 135,000 soldiers. The number could always be adjusted by McClellan, depending on Confederate actions. On April 1, McClellan sailed down the Potomac to prepare his assault.

Three days later, without McClellan’s knowledge, Lincoln held back an additional 33,000 men from McClellan’s attacking force. McClellan, who had already written orders for those men, was not aware of the new arrangement until he had reached the front.

He pleaded with Lincoln to release the troops. “I beg that you will reconsider the order . . . the success of our cause will be imperiled by so greatly reducing my force when it is actually under the fire of the enemy and active operations have commenced.”

Gen. George B. McClellan (1826-1885), U.S. Civil War general and politician. In 1862, McClellan commanded the Army of the Potomac at the Battle of Antietam. (Washington Post files)

Lincoln was adamant: “You now have over 100,000 troops with you. . . . I think you better break the enemy’s line from Yorktown to Warwick River at once.”

At the time, though, McClellan had only about 58,000 soldiers, since many of his troops were either awaiting embarkation back in Washington or still in transit. In a private note to his wife, McClellan fumed, “I was much tempted to reply that he had better come and do it himself.”

He hesitated. Although the rebel force that McClellan faced was far smaller, about 11,000 men, it held an excellent defensive position, most of it behind an impassable swamp and river, 100 to 300 feet wide. To break the Confederate line, McClellan’s men would have to funnel into a two-mile stretch of fortified land, swept from three sides by heavy artillery, without the benefit of their own heavy guns.

Fearing a slaughter, McClellan settled in for a siege. Over the next two weeks, the remainder of his force arrived, but so did another 40,000 Confederates.

He learned then that the 88,000 men left behind had been removed from his control and put under the direct command of Lincoln’s Secretary of War, Edwin Stanton, a lawyer with no military experience. McClellan could no longer control the relegation of troops between his defense and offense.

Then, in a blow that affected Union commanders on every front, Stanton closed down all recruiting stations in the North. From this point on, each Union soldier who was lost — whether from combat or disease — would not be replaced. Four days after the order, 13,047 Federals fell at Shiloh. More than 70,000 would be lost before Stanton’s order was rescinded three months later.

The new strategy played directly into Confederate hands. The horrible reversals over the winter forced the Confederacy to initiate a draft, which prevented those already in the army from leaving and brought into their fold most of the remaining southerners from the ages of 18 to 35. So as the Union Army shrank, the Confederate Army grew.

Confederates also were retooling their strategy. Instead of defending every locale throughout the South, they concentrated their armies on the most important strategic points, Richmond in particular.

After one month, on the night of May 4, the siege forced the rebels to retreat, and McClellan resumed his march on Richmond. Lee stripped troops from the Atlantic coast to the Shenandoah Valley to defend his capital. Confederate records show that in one month, the number of men in front of McClellan’s now-95,000-man army swelled from about 56,000 to more than 115,000. McClellan, who thought that additional Confederates had arrived from the western theater to expand the total to 200,000, anxiously telegraphed Lincoln for reinforcements. He had been promised another 35,000 men when he reached Richmond, but barely 10,000 would ever arrive.

Lincoln and Stanton, meanwhile, failed to take advantage of the newly weakened Confederate fronts. Instead, they spent their time directing the Washington defense force as it got tangled up in a wild-goose chase pursuing Jackson’s small army through the Shenandoah Valley. Even McClellan’s rival, Gen. Irwin McDowell, could see the folly of the venture. Pleading with Lincoln not to redirect his troops from reinforcing McClellan, McDowell wrote, “I shall gain nothing for you there, and shall lose much for you here . . . it throws us all back, and from Richmond north we shall have all our large masses paralyzed.”

Lincoln would not budge. When Jackson slipped away to join Lee at Richmond, more than 60,000 Union troops sat idle in the valley without an enemy to fight.

On Jackson’s arrival, the great Confederate offensive to relieve Richmond began. Without reinforcements, McClellan found his supply line exposed. In seven days of bloody assaults, Lee hammered McClellan’s line back to the James River between Richmond and Petersburg. There, Union gunboats prevented further pursuit. McClellan’s army was defeated, but not destroyed.

Finally, Lincoln and Stanton gave up their roles as strategists and pulled Gen. Henry Halleck from the West to take over as general in chief.

Still within striking distance of Richmond, McClellan now suggested that his army be sent south to take the critical railroad junctions at Petersburg, Va., a strategy that Gen. Ulysses S. Grant would use two years later to win the war. But Halleck ranked the security of Washington higher and decided to advance on Richmond from the north with both Pope’s and McClellan’s armies. On Aug. 3 McClellan was ordered to withdraw from the Peninsula and join Pope.

McClellan has been accused of stalling, but moving a large army without notice is a complex undertaking. McClellan first had to bring back part of his army, which had advanced toward Richmond under Halleck’s orders. He also had to evacuate some 12,500 sick, but few transports were available, most already in use moving another command or transporting prisoners of war. Some of the largest transports could not reach his army because the James River was too shallow. When the army did move on Aug. 14, they had to march 40-55 miles to port.

McClellan sent his infantry before his artillery and cavalry, because the latter two required more time to ship. Almost half of his army got there before they were stopped by Jackson’s men who, unbeknownst to Union generals, had slipped around behind Pope.

As 1,200 of McClellan’s infantry rode the train to reinforce Pope, they found Jackson’s rebels with ample artillery waiting for them. Without cannons, the Federals were sitting ducks and lost a quarter of their men before they could escape. For the next two days, McClellan refused to send the remainder of his forces forward until his artillery was ready to accompany them. A frustrated Halleck overruled McClellan and ordered his troops forward, leaving McClellan without an army. (When Pope was defeated, Lincoln returned the army to McClellan.)

After the battle of Second Manassas, Lee marched north into Maryland and Lincoln called on McClellan to stop the invasion. More accusations of slowness and stupidity were leveled against him, even though he became one of the few generals to defeat Lee, in the battle of Antietam [to be addressed in the next Civil War section in September.] Finally, after the November elections, Lincoln cashiered McClellan.

Two years later, McClellan became the Democratic candidate for president. An army of newspaper writers and politicians sympathetic to Lincoln went after McClellan’s character, questioning and condemning every military action he had taken in his career.

Obscured by all this were some truly great accomplishments. Perhaps the most impressive was building an army from scratch and advancing it to within six miles of the Confederate capital at a cost of 10,000 men — all within the first year of the war. That same feat was only accomplished by one other Union commander — Grant, who lost six times as many men fighting a rebel army half the size and worn out by two years of fighting and attrition.

Perhaps the greatest testament came from Lee. According to Lee’s son, on the afternoon of July 15, 1870, Lee visited his first cousin and lifelong friend, Cassius Lee. When the general was asked which of the Federal generals he considered to be the greatest, “He answered most emphatically ‘McClellan by all odds.’ ”