Place is sometimes vague or undefined in studies of context, and scholars use a range of Census units to measure “context.” In this article, we borrow from Parsons and Shils to offer a conceptualization of context. This conceptualization, and a recognition of both Lippmann’s pseudoenvironments and the statistical Modifiable Areal Unit Problem, lead us to a new measurement strategy. We propose a map-based measure to capture how ordinary people use information about their environments to make decisions about politics. Respondents draw their contexts on maps—deciding the boundaries of their relevant environments—and describe their perceptions of the demographic make-up of these contexts. The evidence is clear: “pictures in our heads” do not resemble governmental administrative units in shape or content. By “bringing the person back in” to the measurement of context, we are able to marry psychological theories of information processing with sociological theories of racial threat.