(A) George McClellan
(B) ** John Pope
(C) Irvin McDowell
(D) Joshua Lawrence Chamberlain
EXPLANATIONS BELOW
Concept note-1: -Did you know? Union Major General John Pope lost about 15, 000 men in the Second Battle of Bull Run (Manassas), along with his reputation.
Concept note-2: -On July 21, 1861, in the first major land battle of the Civil War, a large Union force under General Irvin McDowell is routed by a Confederate army under General Pierre G.T. Beauregard.
Concept note-3: -This success, combined with the defeat of General Irvin McDowell at the Battle of First Bull Run, led McClellan to become Commander of the Army of the Potomac, and later General-in-Chief of all Federal armies upon the retirement of General Winfield Scott in November 1861.