What invention caused the slave trade to explode in the south

Cotton Gin

Explanation:

From 1790 until the Congress prohibited the importation of slaves from Africa in 1808, 80,000 Africans were shipped from Southern Africa. By 1860, about one in three Southerners was a slave. Because of the cotton gin, slaves were now employed on ever-larger plantations where labor was more regimented and unrelenting.

its main object was the establishment of "settlement houses" in poor urban areas, in which volunteer middle-class "settlement workers" would live, hoping to share knowledge and culture with, and alleviate the poverty of, their low-income neighbors.