The Union will have a much much larger army, not only because it did IRL, but a third of the confederate population were slaves and were not allowed to fight, and because there is an almost 20% population gap between the two.
The Union army will have higher number of army because there is about 20% population gap between them and one third of the confederate population were slaves.
During the American Civil War, the Union Army fought for Northern region while the Confederate army fought for the Southern region.
In conclusion, the Union army will have higher number of army because there is about 20% population gap between them and one third of the confederate population were slaves.
