 As a result, social and racial tensions in the city intensified, as native-born residents, migrants, and immigrants fiercely competed for jobs and limited housing due to overcrowding.Tensions eventually simmered into the Chicago race riot of 1919 during the Red Summer era, in which ethnic Irish gangs attacked black neighborhoods on the South Side, leading to the deaths of 23 blacks and 15 whites as well as many arson damages to buildings.In the 1920s, the Chicago Real Estate Board established a racially restrictive covenant policy in response to the rapid influx of southern black migrants who were allegedly feared in bringing down property values of white neighborhoods.