The humiliation faced by northerners at their defeat by Confederate at the first battle of Manassas has lowered their morale. There was resentment in the people about increased taxes and the effect of war on trade. Moreover, Northerners were better equipped with weapons because of industrialization and were expecting victory and defeat was a shock. Some even questioned the leadership of President Lincoln and the war itself.
The answer is: Some questioned the war and Lincoln's leadership.
When the northern states battled the southern states in the civil war, the northern states have larger number of soldiers and more advanced weapons due to early industrialization.
Because of this, the northern citizens supported the cause with full confidence. After hearing that they manage to lost despite having the advantage, some questioned the war and lincoln's leadership.
In general, it is true that Mao was a visionary who slowly lost touch with reality as time went on. He mostly failed in many ways because he tried to push for reforms that his people were not ready for.
