Why was sharecropping called a "new form of slavery?"

Since the north won the war, Slavery was illegal in most states. So the formal slave owners let go of their slaves but not at the same time. Because of the jim crow laws. All minorities were given little rights. So the formal slaves had no where to go but back to the farm, not as slaves but as sharecroppers. I believe they got paid but only a tiny percentage belonged to them and the rest of the profits went to the owners of the plantation.