CHARLESTON, W.Va.

--On March 17, 1862, Gen. George B. McClellan, commander of the Army of the Potomac, began to move his 70,000 soldiers from Washington down the Chesapeake Bay to Fortress Monroe on the James River Peninsula to launch a surprise attack on the Confederate capital at Richmond.

It was expected to be the deciding battle of the American Civil War. Instead, the Peninsula Campaign ended in failure, creating an irreparable rift between President Abraham Lincoln and the general he once believed would lead the Union to victory.

McClellan, a native Philadelphian, was considered the most promising general in the Union ranks at the beginning of the Civil War. The 34-year-old appeared by training and experience to be the ideal officer to lead the North to victory over the Confederate army.

Born on Dec. 3, 1826, McClellan was the son of a prominent surgeon who founded Jefferson Medical College. Graduating second in his class at the U.S. Military Academy, McClellan was brevetted a second lieutenant in the Army Corps of Engineers.

During the Mexican War, he served under Gen. Winfield Scott, who, impressed by McClellan's brilliance as a military engineer and bravery in combat, promoted him to captain. Afterward, McClellan returned to West Point as an instructor of military engineering. When the Civil War began in April 1861, he was promoted to major general and made commander of the Department of the Ohio. In June, McClellan, commanding three times as many troops as the Confederate forces in western Virginia, easily routed the enemy.

Impressed by the victory, Lincoln, reeling after the disastrous Union defeat at the First Battle of Bull Run in early July, gave McClellan command of the Army of the Potomac, the main federal army in the East. The appointment made him second only to Winfield Scott, the general-in-chief. McClellan's immediate duties were to ensure the safety of Washington and to reorganize the army.

Only two-thirds of the Union's 51,000 soldiers were properly trained and fit for duty. During the next eight months, McClellan drilled, disciplined, and reorganized the troops, preparing them to march on Richmond. In the process, he gained the admiration and affection of his troops.