It has been said by men of the period that if there had been more railroads to and in the South, there would not have been a secession or war. Meaning that had more Americans been able to travel around the states the bringing together of all Americans as people, and not as faceless demons, would have softened the rhetoric. Newpapers and the ability to rapidly distribute by wire information, left a gap in perception of opposing views when personal contact is removed. This most probably did add to fears and hatred between the two factions. The ability to insult or express charges against one section of the country, with mass distribution, at the speed of the electrical circuit, without fear of reprisal or personal injury was too tempting not to engage in.
With the growth of the internet, this, is something we have been experiencing in our day. Look at the historic changes in how politics and news works today as opposed to twenty years ago.