Likely the former. In the year prior to the war something like 90% of all cotton exported left from southern ports. Less than 10% was shipped out of New York. Based on tariff collections they weren't showing up packed with imports.
NYC was the #1 cotton export port, followed by New Orleans and Mobile, but I think at quite some distance.
I'd like to see your source for those figures.
I would too. Can’t seem to find it. If you run across any numbers, I’d appreciate a ping.
I’m not talking here about cotton shipped out of a port, but cotton shipped out of a port to overseas.