Increasingly, African Americans find themselves living side-by-side with immigrant newcomers from Latin America, the largest source of today’s immigrant population. Research on “Black/Brown” relations tends to a priori define groupness in ethnoracial terms and gloss over potential nuance in inter-group relations. Taking an inductive approach to understanding how African Americans interpret the boundaries that result from immigration-driven change, this paper draws on fieldwork among African Americans in East Palo Alto, California, a Black-majority-turned-Latino-majority city, to examine how African Americans construct multiple symbolic boundaries in the context of a Latino-immigrant settlement. Blacks’ rendering of these boundaries at the communal level invokes ethnoracial boundaries as a source of significant division. They see Latinos as having overwhelmed Black material and symbolic prowess. However, accounts of inter-personal interactions evince symbolic boundaries defined by languageand neighborhood tenure that render ethnoracial boundaries porous. Respondents note intra-group differences among Latinos, pointing out how the ability to speak English and long-time residence in the neighborhood are important factors facilitating ties and cooperation across ethnoracial boundaries. The findings point to the importance of intra-ethnoracial-group differences for inter-ethnoracial-group attitudes and relations. Adopting ethnographic and survey research practices that treat boundaries as multiplex will better capture how growing intra-ethnoracial-group diversity shapes inter-ethnoracial-group relations.