Abraham Lincoln was the political leader for the Union. He was the 16th President and politically guided the Union during the American Civil War.
Ulysses S. Grant was the military leader for the Union. He was accompanied by many more including William T. Sherman.
For the Union, their strategy was the "Anaconda Plan". Which was to "slowly suffocate the south economically. A blockade to prevent the south from trading with the world. The army would divide and isolate various portions of Confederacy.
One of the many advantages the Union had was their population. More than 22 million people. Meaning there was more people to engage in the war and people to help the men who were fighting.
Another advantage to the Union was they were financially stable. They were able to keep weaponry coming for a battle. It made it easier on the soldiers that the union was financially stabled.
Another advantage that the union had was that they had many factories. The were industrialized.