While the northern states gradually abolished slavery in the decades after the American Revolution, the southern states became even more firmly committed to the institution. African American slaves made up much of the labor force and wealth of the South, and the institution of slavery was essential to defining its political, economic, and social structure. At the same time that the Northwest Territory was being populated and transformed into new states, southerners flooded west into the Lower and Deep South—Alabama, Louisiana, Mississippi, Kentucky, Tennessee, Arkansas, and Missouri—pursuing their fortunes through cotton and sugar. An estimated one million African American slaves were torn from their families with little hope of seeing them again and were transported west by foot, wagon, or boat to build these new plantations.