While the Erie canal had obvious advantages, there were Southern possibilities.
Washington also championed the Kanawha canal project.
https://www.wvencyclopedia.org/articles/964
A turnpike wasn’t a disqualification (for Kanawha ot Potowmac) . And these were southerners in the NW Terrs who would use it.
http://www.envisionthejames.org/detail/james-river-and-kanawha-canal/evj6e320620cd3a8cf84/
“Then followed the War Between the States and the consequent destruction and deterioration of canal works. “And now the canal, after a fair and costly trial is to give away to the rail,” George Bagby wrote sometime after Appomattox, “and I in common with the great body of Virginians, am heartily glad of it. It has served its purpose well enough, perhaps, for its day and generation. The world has passed it by... The dream of the great canal to the Ohio... must be abandoned along with other dreams.”
In 1880 the canal system was sold to the Alleghany Railroad Company, and tracks were laid on the towpath, thus preventing canalboat traffic.”
Lot of historical trends going on. Basically though, the Southern slave-based capitalists made choices that were not future-oriented.
“Washington also championed the Kanawha canal project.”
For a southern route. The James is in the south of Virginia. A canal there connects to the west but it’s not very close to the Northwest Territory.
“A turnpike wasn’t a disqualification “
It defeats the advantage of boats and barges being able to efficiently carry much heavier loads than pack animals. A turnpike as part of a canal system requires pack animals and the unloading and reloading of shipments.
The Erie didn’t require portage and was more efficient.