Abraham Lincoln, a Republican was the president of the United States also known as the Union. He was elected in 1860 and strongly opposed slavery. Lincoln later wrote Emancipation Proclamation which freed enslaved people in the Confederate States.
Important military leaders included General Ulysses S. Grant, William T. Sherman, and George B. McClellan. These men were involved in many significant battles during the War.
Winfield Scott proposed the Anaconda strategy. This plan was designed to suffocate and choke the South. The Union planned to impose blockades to halt Southern trade with Europe, which was vital to their economy. The Union also planned to then divide and isolate important parts of the SOuth.
As a result of the growing factories in the North, cities also grew rapidly. This led to the population of the North skyrocketing. The North's population had reached 22 million. The abundance of people led to a lot of war support.Not only were there more troops, but there were also cooks, nurses, conductors, spies and many more.
Transportation was a huge advantage to the North because it made getting supplies to troops much easier, it also made delivering messages faster. The North was home to 72% of the country's railroad tracks, making the above-mentioned things much easier.
Since the Union was still the United States of America they still had access to the National Treasury and bank reserves. The North could actually afford the cost of a war because of all of these financial resources.