(A) George B. McClellan replaced McDowell and taught the army how to fight with their hands.
(B) McDowell was not replaced but did retrain and reorganize the army.
(C) ** George B. McClellan replaced McDowell and he retrained and reorganized the army.
(D) Lincoln took the position and kept the army the same.
EXPLANATIONS BELOW
Concept note-1: -For the Union, Lincoln removed McDowell from command and replaced him with George B. McClellan, who would retrain and reorganize Union troops defending Washington into a disciplined fighting force, thereafter known as the Army of the Potomac.
Concept note-2: -Irvin McDowell, the commander of the Union Army of Northeastern Virginia, was relieved and replaced by Maj. Gen. George B. McClellan, who set about reorganizing and training what would become the Army of the Potomac.
Concept note-3: -On November 1, 1861, President Abraham Lincoln names George Brinton McClellan general in chief of the Union army, replacing the aged and infirm Winfield Scott. In just six months, McClellan had gone from commander of the Ohio volunteers to the head of the Union army.
Concept note-4: -In 1862, McClellan’s Peninsula Campaign unraveled after the Seven Days Battles, and he also failed to decisively defeat Robert E. Lee’s Confederate Army at the Battle of Antietam. Frustrated by McClellan’s cautious tactics, Lincoln removed him from command.
Concept note-5: -Irvin McDowell was a Union general during the American Civil War (1861–1865). He commanded the army that was defeated at the First Battle of Manassas on July 21, 1861, the first large land battle of the conflict.