History [ edit ] With its factories, steel mills and meat-packing plants, the South Side saw a sustained period of immigration which began around the 1840s and continued through World War II . Irish , Italian , Polish , Lithuanian and Yugoslav immigrants, in particular, settled in neighborhoods adjacent to industrial zones. [20] The Illinois Constitution gave rise to townships that provided municipal services in 1850. Several settlements surrounding Chicago incorporated as townships to better serve their residents. Growth and prosperity overburdened many local government systems. In 1889, most of these townships determined that they would be better off as part of a larger city of Chicago. Lake View, Jefferson, Lake, Hyde Park Townships and the Austin portion of Cicero voted to be annexed by the city in the June 29, 1889 elections. [1] [21] [22] After the Civil War freed millions of slaves, during Reconstruction black southerners migrated to Chicago and caused the black population to nearly quadruple from 4,000 to 15,000 between 1870 and 1890. [23] In the 20th century, the numbers expanded with the Great Migration , as blacks left the agrarian South seeking a better future in the industrial North, including the South Side. By 1910 the black population in Chicago reached 40,000, with 78% residing in the Black Belt. [23] [24] Extending 30 blocks, mostly between 31st and 55th Streets, [25] along State Street , but only a few blocks wide, [23] it developed into a vibrant community dominated by black businesses, music, food and culture. [24] As more blacks moved into the South Side, descendants of earlier immigrants, such as ethnic Irish, began to move out. Later housing pressures and civic unrest caused more whites to leave the area and the city. Older residents of means moved to newer suburban housing as new migrants entered the city, [26] [27] driving further demographic changes.