False premise. Charleston and New Orleans are just two examples of Southern seaports active in international trade. Both cities had shipbuilding traditions, and both ports were hundreds of miles closer to the cotton.
If the South really did purchase most of the imported goods and by consequence pay most of the tariffs on them as your side has repeatedly asserted, then there was no good reason why the South couldn't compete for shipping as well. We all know there was no Federal law preventing them from doing so.
A distortion. Pea has given the info to demonstrate that imports were disproportionate, but a simple majority? No.
Seems to me that after years of investment in the shipping industry, the Northeastern merchants were poised to take advantage of the new laws. I don't know why this is so difficult, maybe the coal analogy just isn't working.
It's not just the geography, though that plays a major role in trade, but pretend that Congress passed laws favorable to OS vendors; would you expect that some peon like me could start up a company and turn it into an empire such that I could receive as much benefit from said law as an established giant such as Microsoft?