When Northern soldiers proclaimed they were fighting to "save the Union," what did that really mean? The Union is an idea or concept. Why would men be willing to suffer so much for something so vague?

1 They cared only about the fact that slavery was still allowed in the South.
2 Northerners were concerned about their future and about what would happen if secession was accepted.
3 The Constitution did not allow for the secession of states, and without law, the country would fall into chaos.