Answer:
In my personal opinion, I think the Union(North) would win over the Confederacy(South)
I will group into several reasons
1. Resources/economy
The North obviously had a more wide variety of economical resources compared to the south. The South only relied on their cotton resources from slavery which is bad. Relying on a single type of resource means there wouldn't be any backups.
2. Numbers/troops
Now 11 states had left the Union and realistically they would have about a million total. Obviously, Union still had more number in shear troops almost doubled the Confederacy.
3. Strategies/Military leader
While Union did have more numbers of soldiers the Confederacy had better strategic military leaders like Stonewall Jackson. The Union had a weaker leadership compared to the Confederacy leading them to change their leaders multiple times.
4. Setting/places battles took
During the Civil War, the majority of the battles were in the Southern lands and the Union later took advantage of this. One of the military leaders Ulysses S. Grant used a battle strategy called total war. It was basically a strategy to burn or destroy any kind of valuable resources in the Southern's land. Now like I said before the only resources Southern relied on was cotton and the total war strategy was harsh on them.
Step-by-step explanation: