Final answer:
The South's geography favored the cultivation of crops like cotton, which necessitated a large labor force provided by slavery. The prohibition of international slave trade in 1807 and the profitability of cotton solidified slavery's role in the economy, leading to its geographical expansion.
Step-by-step explanation:
The geography of the South played a pivotal role in the rise of slavery due to the region's suitability for cultivating highly profitable crops like cotton, rice, and tobacco.
The vast land required for such plantations necessitated a large labor force, which was provided by enslaved Africans via the Transatlantic Slave Trade.
The invention of the cotton gin increased cotton production and solidified the need for cheap labor, further entrenching slavery. Additionally, the profitable cotton production also led to the internal domestic slave trade, as the outlawing of international trade in 1807 spiked the demand for slave labor within the country and transformed the Southern economy.
Southern states sought to expand their territories to maintain their economic and political power, further spreading slavery into new regions.