Why do we still have original sin if Jesus died on the cross to absolve our sins?

Original sin is supposedly the aftermath of Adam and Eve being banished from the Garden of Eden. At one time the Catholic Church taught that newborns came into this world with original sin and upon being baptized they would be absolved. Un-baptized babies would go to Limbo, which no longer exists. I don't know what the CC teaches today, if someone does know please let us know.