This dissertation examines the making of free soil and black freedom, as well as the abolitionist movement in southwestern Pennsylvania. I frame the region as a borderland between the free North and the slave South, where the status of African Americans was somewhere between slavery and freedom, as well as a crossroads between the abolitionist movement in the East and the Old Northwest. By doing so, I hope to understand how geography (physical and political) influenced ideas about race and the types of strategies abolitionists favored in their fight against slavery and for black rights. I argue that the roots of free labor ideology—a belief that emerged in the 1850s that slavery (and, for some whites, free blacks) should be prohibited from western territories in order to allow free white men to earn a living wage—can be traced to the 1780s when southwestern Pennsylvania was one of the first territories opened to westward expansion and where the place of black people in American society remained uncertain.

Alongside this nascent idea of free labor emerged an oppositional culture created by African Americans and their white antislavery allies that was shaped by their geographic location, worksites, institutions, and living conditions. This led to the formation of counter ideas about free soil, the west, black freedom, race, and citizenship. Many white southwestern Pennsylvanians adamantly opposed these ideas fearing that interracial social relations, labor competition, and the possible migration of blacks into the region would degrade the economic independence of these households, turning whites into a dependent and degraded class.