This question can have many answers but ill try to answer it in the north slaves werent profitable so most northerners didnt have slaves and eventually slavery was seen as morally wrong in the north so in the south once abraham lincoln became president the south became its own coutry and the civil war began so after the north won slavery was abolished in the south.
The answer is true, and the book he wrote is called "The Jungle", which he wrote in 1906.
