Am very much aware of that. Several years ago was involved in a discussion with someone who said their family was involved in the shipping business in the Northeast, and they explained how the whole thing worked. I think it may have been rust bucket.
Disallowing ships to go from port to port made it uneconomical for an oceangoing vessel because they could only take on a full cargo at ports like New Orleans. The packet shipping system which was ran by New York, would move from port to port acquiring enough cargo which they would then deliver to an ocean crossing vessel. Alternatively it could be an ocean crossing vessel going from port to port collecting cargo, though my reading indicates the packet system was the dominant method.
With foreign ships unable to do this, it wasn't cost effective to go anywhere but New Orleans, and of course all those contracts were bought up by New York interests.
Indeed most cotton that went overseas did go out through Southern ports.
Through New Orleans mostly. New Orleans was the primary shipping hub for all cotton produced anywhere near the Mississippi river, which was a vast area.
All of it was controlled by New York.
You asked me that about a year ago, DiogenesLamp.
Here is a link to my reply back then: Link
And you did remember who had made the remark you were trying to remember: Link 2
You remembered that it was a poster named "WarIsHellAintItYall", who hadn't posted since 2016. I had been on the thread at the same time as that poster.
Ships bringing imports to the US went to the ports that provided the best access to consumers. That was New York (also Boston, Philadelphia, Baltimore). New York was valuable because the city's railroad network made a vast area with much of the country's population easily accessible. New Orleans and other Southern cities didn't provide access to as large a pool of consumers, so imports weren't delivered there.
An article here recounts the problems that led to Charleston's decline as a seaport:
A healthy port, after all, must rely on a thriving hinterland and an effective transportation network to feed it. Hemp grown in eastern Kentucky, for example, was used to bundle southern cotton. But to reach South Carolina, the hemp had to be sent north by rail to the Great Lakes, by barge to New York, and then by coastwise vessels to Charleston. In this era, “New York has a hinterland that stretches west to Indiana” and into the South itself, says Scott Reynolds Nelson, a historian at the College of William & Mary. “South Carolina has a hinterland that doesn’t get to Tennessee.”
You keep repeating that foreign shippers could have carried goods more cheaply and that US shippers raised prices because of the Navigation Act, but you don't provide any real evidence. Competition between domestic shippers would have kept the cost of coastal shipping from going too high.
Your idea that there was some Northern monopoly of coastal shipping runs aground when we look at the domestic slave trade. So far as I've been able to find out slave traders in Virginia had no trouble renting space on or chartering or even buying and operating ships to send slaves to New Orleans for sale. Article about the brig Uncas. More about the four ships owned by Franklin & Armfield.
There was no Northern monopoly of coastal shipping or of transatlantic shipping. The problem was that there was no Southern market for any foreign goods as big as the Greater New York market was, or as big as the market for slaves in the boom days of cotton growing on the Mississippi was. Also, Southerners didn't put as much effort into shipping as Northerners did. It wasn't a priority for them.
No, the truth is, you don't know who owned those packets because there were hundreds of them, of all sizes & capacities, many locally manufactured to take smaller loads shorter distances, down river.
The idea that all or even most were owned or "ran" by "New York" is simply not supported by any objective evidence.
And if we were truly honest, we'd admit that "New York" could be anyone, including family members of wealthy Southern planters, sent there for schooling, stayed to "learn the business".
And we know that Southerners did own ocean-going ships because some were famously caught with cargos of slaves in the years just before the Civil war.
DiogenesLamp: "Through New Orleans mostly. New Orleans was the primary shipping hub for all cotton produced anywhere near the Mississippi river, which was a vast area."
It's true that New Orleans was the largest Southern port, by far. But it was far from the only one to ship cotton directly to European customers. Mobile & Galveston on the Gulf Coast, Savannah & Charleston could all ship directly, as the need arose.