Milton and Rose Friedman explain how tariffs discriminate against exporters and export-dependent regions on an even more fundamental level in their bestseller, Free to Choose (Avon paperback, 1980, p. 38):
If tariffs are imposed on, say, textiles, that will add to output and employment in the domestic textile industry. However, foreign producers who no longer can sell their textiles in the United States earn fewer dollars. They will have less to spend in the United States. Exports will go down to balance decreased imports. Employment will go up in the textile industry, down in the export industries. And the shift of employment to less productive uses will reduce total output.
I read Free to Choose when it came out. And again I will point out the danger of applying 20th century theory to 19th century economies which were not as advanced. In 1860 the British textile industry had no peer in the world. They dominated production, even with U.S. protections, and in order to continue that level of production they needed the raw materials, cotton. The world’s greatest producer at that time was the U.S. and we exported more than 3 million bales per year, almost all of them to Britain. There are no statistics that I’ve ever seen that indicates that the tariff laws in effect ever impacted Southern cotton growers, quite the opposite. Cotton exports had been growing year after year in a virtually unbroken span dating to long before the rebellion.