The war between the states was an economic war between the oppressive industrial North and the agricultural South regarding States’ Rights. Abraham Lincoln made slavery a cause to get behind 2 years into the war because of draft riots in the Northern cities. The Northern soldiers didn’t have a cause to fight for. The Southerners did.
The big draft riots happened after the Emancipation Proclamation.
The Northern soldiers didn’t have a cause to fight for.
The flag. The country. The union. The Constitution. Those things mattered a lot in the 19th century.
The Southerners did.
Southern soldiers came to wonder just what they were fighting for and whether it was all worth it.