How did the economic role of African Americans change between 1860 and 1880?

Slavery was effectively abolished by the triumph of the North against the South in the Civil War (1861-1865). The 14th Amendment granted citizenship to all African Americans in 1868. Black slaves in the southern states ceased to be forced labor, but they turned into cheap labor for plantations; either they were usually paid very little or were victims of legals norms that sought to perpetrate their de facto state of slavery and their misery. In the North, the African American population provided labor for industries. Economic growth, a better political environment and new opportunities opened by industrial developement estimulated large black migration from Southern rural villages and towns to cities in the North in the second half of the 19th century. African American migraton contributed thus to fast urbanization and the growth of cities.