OTL growth (1865-1898):
"American what production increased by 256 percent, corn by 222 percent, refined sugar by 460 percent, coal by 800 percent, steel rails by 523 percent, and the miles of railway track in operation by over 567 percent. 'In new industries the growth, starting from near zero, was so great as to make percentages meaningless. Thus the production of crude petroleum rose from about 3,000,000 barrels in 1865 to over 55,000,000 barrels in 1898 and that of steel ignots and castings from less than 20,000 long tons to nearly 9,000,000 long tons.
...
The role of foreign trade in the US's economic growth was small indeed (around 8 percent of its GNP derived from foreign trade in 1913, compared with Britain's 26 percent), but its economic impact was considerable. Traditionally, the United States had exported raw materials (especially cotton), imported finished manufactures, and made up for the usual deficit in 'visible' trade by the export of gold. But the post-Civil War boom in industrialization quite transformed that pattern. Swiftly becoming the world's largest production of mamnufactures, the United STates began to pour its farm machinery, iron and steel wares, machine tools, electrical equipment and other products onto the world market." (from The Rise and Fall of the Great Powers).
It still has most of its territory, particularly the highly industrialized part. I wouldn't say there will be no damage at all, but it won't be crippling by any means.
Cotton is not king post-war.