Final answer:
From 1840 to 1860, the price of a 'prime field hand' increased by about 100 percent due to inflation and the rising importance of enslaved laborers in the cotton market.
Step-by-step explanation:
From 1840 to 1860, the price of a 'prime field hand' increased by about 100 percent. During this time, prices had nearly doubled as a result of standard inflation and the increasing importance of enslaved laborers in the cotton market. For example, in 1845, 'prime field hands' sold for an average of $1,600, which was a significant increase from the average cost of $700 in 1838.