Final answer:
The 19th-century U.S. cotton industry resulted in the movement of a large number of slaves to different parts of the South to support the growing demand for cotton as a cash crop.
Step-by-step explanation:
The U.S. cotton industry in the 19th century led to b) the movement of 835,000 slaves to different parts of the South. This was primarily due to the creation of the 'Cotton Kingdom' during the first half of the nineteenth century, which dramatically transformed the Southern economy and landscape. Eli Whitney's cotton gin invention made the large-scale production of short-staple cotton profitable. As cotton became a lucrative cash crop, the dependence on slave labor increased, and the domestic slave trade grew, allowing for the expansion of cotton production across the South. Consequently, there was a significant migration of enslaved people to labor-intensive cotton fields as new lands were cultivated for cotton production.