NEED HELP I WILL GIVE BRAINLIEST PLEASE What caused the great economic inequality between the rich and poor during the Progressive Era?

People who remained on farms were stuck in poverty.
Urban factory workers had to live in crowded tenements.
Business owners did not share profits with their employees.
There was a large wave of people emigrating from poorer countries.

im pretty sure it has something to do with the end of ww1

abraham lincoln, according to anyone who was connected with agriculture, represented the worst of northern politicians. shortly after lincoln was elected, south carolina seceded from the union. they along with other southern states, retained their anger. in a way, it was their own fault: the democrats were split in the south. some wanted slavery to be extended in other states that were about to join the union and some didn't want it badly enough. lincoln had a solid backing from his party: the republicans were united in not wanting slavery to be expanded.