How many Americans were in the American civil war?

Answer:
Before secession the United States had a population of 31 million. The Union had 23 million, and the South had only 9 million. 3.5 of that were slaves (around 150,000 were free blacks) and not counted as apart of the fighting men. The Union had 23 million who could fight, the South had only 5.5 million. The numbers were definitely in the Union favor.
First answer by Meggerz4584. Last edit by Meggerz4584. Contributor trust: 1 [recommend contributor recommended]. Question popularity: 2 [recommend question].