This dissertation examines why the Great Migration to Appalachia could result in both promise and peril for African Americans. It argues that the racial violence of the Long Red Summer, and the formation of sundown towns in its aftermath, can be best understood by putting a consideration of labor back into labor history. At different locations within the kingdom of coal in Appalachia, the relationship between capital and labor produced distinct social relations and racial ideologies. In other words, the kinds of work people did, who they worked with, and how and where they lived, manufactured ways that they conceived of – and acted on – race. The industries of railroading and coal mining serve as a point of comparison, revealing how and why some white workers’ desires to exclude Black labor from the job transformed into efforts to expel them from communities altogether.