You used to put great store in facts as demonstrated by records from the past. I urge you to resume that standard of objectivity.
What does this map tell you?
Where is all the money going?
Who is that dude standing there in Clovis with his smartphone?
It tells me that New York had good port and transportation facilities and could send goods cheaply to large numbers of paying customers.
What does this map tell you?
And how about this one?
Bear in mind:
1) A lot of those Southern railroads were on different gauges making through-shipping difficult.
2) A lot of that Southern population wasn't actually paid for their labor in money that they could use to buy things.