rapid economic growth generated vast wealth during the gilded age. new products and technologies improved middle-class quality of life. industrial workers and farmers didn't share in the new prosperity, working long hours in dangerous conditions for low pay. gilded age politicians were largely corrupt and ineffective.
a runaway slave, because they saw the terribly acts of slavery and actually was in slavery. they would be happy to abolish slavery so their viewpoint would be positive on ending it
a plantation owner would not want it abolished neither would a southern politician (since it was more racist back then) nor a temperature reformer because they has slaves working for them.