Slavery itself was never widespread in the North, though many of the region's businessmen grew rich on the slave trade and investments in southern plantations. Between 1774 and 1804, all of the northern states abolished slavery, but the so-called “peculiar institution” of slavery remained absolutely vital to the South. For the South, slavery was never solely an economic system, but also provided the racial underpinning of southern social structures when, in 1860, 95% of African Americans lived in the South.