Causes of the American Civil War - pt.1: Was the American Civil War over Tariffs?

 We often see the claim "The [American] Civil War was over tariffs" coming from Lost Causers. But how true is this?

Well, let's start off with this question first: How much of the Federal government's revenue did the Southern states actually pay?

As per this image, taken from page 71 of this report from the NY Chamber of Commerce, we can clearly see that NYC alone consistently accounted for the overwhelming majority of America's foreign trade (around 2/3rds). As per this selection of pages from that report, we can see that NYC alone handled a far higher percentage of the goods subject to duties and tariffs. In 1859, for example, NYC alone paid about 2/3rds of Washington's tariff revenue. This is, of course, excluding other major Northern ports like Boston and Philadelphia. The only substantial port in the South at the time was New Orleans. Therefore, the overwhelming portion of tariffs were paid by the North. It therefore follows that if tariffs had been the cause of secession, quite a few more Northern states would have joined the rebellion. This post on the Dead Confederates blog elaborates a bit more on certain aspects regarding numbers.

This Dead Confederates post helps visualize just how much of the Federal Government's tariff revenue was paid by each of the major ports in FY 1859.

Now, granted, the tariffs certainly helped protect Northern Industry. However, this was still not nearly enough of an extra economic burden on the South to cause secession, especially given that tariffs were at a historic low in 1859-1860.