What social impact did the phenomenon shown in the map have on northern midwestern and western cities?

The phenomenon depicted in the map likely refers to demographic shifts, such as urbanization or migration patterns, which significantly impacted northern midwestern and western cities. These shifts often led to increased diversity, as populations from various backgrounds moved to these areas in search of opportunities. Additionally, urban infrastructure and housing demands surged, prompting both economic growth and challenges like gentrification and social inequality. Overall, these changes reshaped the cultural and economic landscape of these cities.