So the navigation act of 1817 was the only reason in the world, that Europeans shipped to New York or other Northern port. Has nothing to do with the fact that New York had more capacity for ships than all Southern ports combined, that it was two day closer sailing. none of these factors applied, only the Navigation act of 1817. So the millions of bales of cotton that left New Orleans, Mobile, Charleston, Savannah between 1817 and 1860, were all hauled out by Northern ships.
No, it wasn't. New York was 800 miles closer than Charleston, it had better harbors, better docks, warehouses and every other sort of facility. New York had plenty of natural advantages to induce traffic to go there. The laws just made it so that other ports couldn't compete with their natural advantages.
The only thing that could have induced people to carry shipping traffic 800 miles further to the South was a greater profit, but so long as the Navigation act was in effect, It was hard for foreign ships to make profit going an extra 800 miles to have to pay the same tariff duties.
With Foreign ships effectively kept away from visiting these other port cities, American ships could use their monopoly to price gouge way above the market value of the free market.
Change the cost of the tariff duties, or allow foreign ships to visit more than one port, and suddenly it becomes very profitable for them to go that extra 800 miles.
Important to remember that about half of all cotton exported in, say, 1860 shipped directly from New Orleans to customers in Europe.
On their return those ships brought imports which made New Orleans the number 4 US port for Federal tariff revenues, after New York, Boston & almost tied with Philadelphia.
Somehow the 1817 Navigation Act seems to have had no effect on New Orleans.