According to John Green, why did the North lose several battles during the
beginning years of the Civil War?
Outdated weaponry
Fewer people in their army
Ineffective Generaling
They had no advantages

Ineffective Generaling

Explanation:

According to John Green in the series, Crash Course US History, the North lost several battles during the beginning years of the Civil war due to ineffective leadership from the Union Generals. A term he called Ineffective Generaling.

This was in reference to the ineffectiveness of leaders such as Maj. Generals  Benjamin Butler, John Pope, Ambrose Burnside and even the overly indecisive and cautious George McClellan all of whom allowed the Confederacy to gain an advantage in battles against the Union which was larger and better equipped.

c. the passage of the fifteenth amendment