However, when the National Road reached Indiana in 1829, its impact on that state was enormous culturally.
You see, there was a Black Swamp between northern and central Indiana and Ohio. It was called the Black Swamp because it was so thick that light could not penetrate the canopy of trees. You couldn’t see your hand in front of your face. It also emitted swamp gas that made it dangerous to travel with a flame to light your way.
The result of this swamp was that Ohio residents coming to Indiana had to go north to Lake Michigan or south to the Ohio River to travel easily into Indiana. For this reason, Indiana was almost exclusively a Kentuckian culture and spoken dialect until the National Road came.
The settlers from the east brought their ideas and politics. They clashed with those of Indiana and set up serious violence during the Civil War.