From 1811 to 1840?
To analyze this data in light of the larger picture, how many of these were ocean going trade ships, how many ships were built elsewhere, and did the construction stop after 1840?
What percentage of the overall picture does this represent? As i've said, the letters from Union soldiers saying they couldn't wait to get into the fight so that they could free slaves do exist, but weren't really representative of all the letters sent back home from Union soldiers during the war.
To highlight them and claim they are representative of the larger picture is an effort to deceive.
How do these New Orleans ships fit into the larger picture?
And I will grant you that of all the Southern ports, New Orleans demonstrates the greatest quantity of trade as shown by that tariff map. So that's your best case for your argument. The other ports are not likely to look so good for your point.
My understanding is that Southern ports like Charleston & New Orleans had thriving shipbuilding industries up until the time when steamships took over the market.
So the loss of shipbuilding had nothing to do with Navigation Acts or other special laws, and everything to do with new technologies.
It's also important to remember that whatever "special privileges" Washington D.C. awarded were overwhelmingly passed by Southern Democrat controlled Congresses and signed by Southern Democrat presidents or their Doughfaced Northern Democrat allies.
This includes nearly all the tariffs before 1861.
That's why the real reasons for secession were not alleged "crimes" committed against "the South", but rather Southern Democrats' fears of what Northern Republicans might do when they first came to power in 1861.