In their efforts to mobilize the resources they need to start and run their businesses, pioneer entrepreneurs from a first-generation, low-resource immigrant community exemplify the interactive relationship between social capital and social networks: the individual social capital entrepreneurs have affects their position within a network, and their network position shapes how much access to latent social capital they have. Throughout this dissertation, I use concepts from social network analysis to describe the structural aspects of migrant entrepreneurs' relationships. I also draw on extensive ethnographic data to understand the social context and decision-making processes that surround migration, settlement, and entrepreneurial outcomes. I tell a processual story, creating a "life-cycle" of immigration, settlement, labor market incorporation, and entrepreneurship. Each stage requires different forms of social capital and transforms an actor's social network differently. Different amounts of legal capital, which refers to the kind and quality of legal status a migrant has, also affect migrants' microeconomic behavior and the structure and composition of their social network. The process of assembling the people and resources needed to start a business in a first-generation immigrant community without ethnic resources or shareable capital elevates a pioneer entrepreneur's network topography - the combination of their structural social capital and their aggregate social capital - both within and externally to their co-ethnic network. Consistent with existent findings on immigrant entrepreneurship, I find that pioneer entrepreneurs depend on strong, bonding ties with family members in their business operations. However, I also find that pioneer entrepreneurs in the formal economy depend substantially on ties with non-co-ethnic partners to start and run their businesses. As such, they are the vanguard of their communities' social and economic incorporation into American society. Framing migrants' social networks as a dependent variable offers new insights into the ways that broad social forces shape microeconomic behaviors and enable or constrain incorporation. In so doing, I show that pioneer entrepreneurs' relationships are dynamic, diverse, responsive to new social and economic contexts, and resilient