On the railroad(s):

I only speculate that they began in the north because of where government was- it was a starting place. Not to exclude the south- and that the first major railroad wasn't completed until after slavery and Lincoln 1868. And if slavery was allowed without the invention of air conditioning, then industrialization just doesn't seem to be the missing link of factories to exist in the south. In 1992 I worked in a factory in Georgia- no air conditioning- 12 hour shifts.