"The fear was free trade with Europe and Charleston and direct competition with the markets."

Well, I see that I am not going to be able to convience you that in my opinion that "free trade" would mean a loss of market share in the import trade into the New York and Boston Harbors. If that trade was going to Charleston. And if Charleston was NOT a part of the United States then New York and Boston wouldn't be collecting the revenue for the United States from that "Free trade".

So that "free Trade" would equate to an overall loss of revenue for the United States from Tariffs.