How does explain what he considers the south’s economic backwardness

The south of the country remained an extremely backward region; slavery reigned here. The basis of the South's economic backwardness was rooted in agrarian relations. No production, even the most labor-intensive, can be profitable if the labor force consumes nine-tenths of the produced, because there are still investments in the purchase of land, buildings, equipment, supplies, etc. In this situation, the economy cannot develop successfully. The irrationality of the use of slave labor was that it was impossible to change the amount of labor in accordance with fluctuations in the business cycle. Slavery preserved the backwardness of the South. Cities, with the exception of port cities, did not grow. In the South, the proportion of urban population did not exceed 10%. Industry did not develop; almost all industrial goods, in particular clothes and shoes for slaves, were bought by planters of the South at northern manufactories or produced on their own farms.

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