In the early decades of the twentieth century, large numbers of African American and White Southerners migrated from the rural South to the urban Midwest as part of the most significant internal migration in US history. This is a linguistic study of the Southern migrant experience in Detroit, a city with a reputation of being the most racially polarized and residentially segregated urban area in America. Although African American and Appalachian White southern migrants and their descendants are two groups that are separated by ethnicity, they share a regional affiliation with the South as well as Southern cultural characteristics. This situation provides a unique opportunity to examine ways in which the interaction of ethnicity and regional affiliation give rise to systematic patterns of language variation and change and phonetic restructuring as a result of language contact. Linguistic effects of large-scale migration for these two Southern groups across three generations of speakers are described and compared to the surrounding dialect norms of Midwestern Whites, through acoustic analysis of portions of the vowel systems. The quantitative acoustic analysis is interpreted with reference to rich qualitative data obtained through the author's four years of ethnographic fieldwork.