I have no doubt it was. Why would anyone need to use it? The import taxes there were the same as they were in New York, and it was 800 miles further south. Why would anyone go there?
Well let's say you could make 40% more profit going there. Would that change your mind? I think it would have done for most back in that era.
Or perhaps you knew that, but didn’t want to admit it.
More like I have no idea what you are trying to get at, or why you think the particular condition of Charleston is especially relevant.
Charleston wasn't much of a port prior to secession, but with secession, it would have become greatly more significant. 13% tax versus 45% tax is why Charleston would have taken business from the Northeast. New Orleans would have been the primary beneficiary, but other ports in the South would have benefited as well.
You said Charleston’s decline as a major shipping port was due to the Civil War. In point of fact that fall began long before.
“This was a humiliation for the once-famous port city that had dominated maritime trade in the American South in colonial and early antebellum days….
From the 1730s to the early 1800s—the golden age of deep-water sailing ships—South Carolina’s plantation economy thrived on maritime global trade and the hundreds of ocean-borne vessels that docked in Charleston each year to load rice and cotton for European markets…
…In the years before the American Revolution, Charleston was the fourth largest city in British North America but easily the richest. Its wealth dominated the rest of the raw southern outback, with perhaps the exception of Virginia. Visitors were awed by the city’s glittering society…
… P.C. Coker, an independent scholar of local maritime history, has described the thinking of a typical colonial Carolina merchant who had 1,200 pounds to invest in the 1730s. With that sum, a merchant could build and outfit a 200-ton seagoing vessel, but he would risk his investment with storms, wars, fires, groundings, and pirates. Or he could pour his money into a dozen slaves and a 500-acre plantation, where he could grow rice and indigo, which fetched high prices. The choice was simple: purchase slaves and a plantation and charter someone else’s ship to send produce to Europe….
… By 1800, Charleston was steadily losing maritime trade to other cities. Greater precision in navigation and improved vessels allowed ship captains to sail directly from Europe to New York. Ships no longer had to travel the southerly route via the Caribbean and Charleston. The faster transatlantic route between New York and Europe left Charleston out of the loop.
Many British and New England merchant firms in the 1820s began avoiding Charleston because free black seamen could not enter the city without a hefty bond being posted..”
The decline began LONG before your boogie man of import taxes, and was due entirely to the choices made in South Carolina.