What discovery led to George B. McClellan's victory over Robert E. Lee at Antietam?

Question

(1 point)
Responses

General McClellan found the Confederate troop roster.
General McClellan found the Confederate troop roster.

General McClellan found General Lee's battle plan.
General McClellan found General Lee's battle plan.

President Lincoln uncovered the South's European alliance.
President Lincoln uncovered the South's European alliance.

Union troops studied Confederate fighting tacti

Answer 1

The discovery that led to George B. McClellan's victory over Robert E. Lee at Antietam was that General McClellan found General Lee's battle plan.