p. 122: Suggests that while historians have focused on the spatial patterns within cities, the role of geography in understanding how cities form, function, and dysfunction has not been fully investigated.

p. 122: “Migration and immigration, deindustrialization, suburbanization, segregation, redlining, urban renewal gentrification, and sprawl—topics that dominate urban and planning history literature—all have a spatial dimension that traditional historical narratives often fail to fully investigate.”

p. 123: Points to GIS as one way to investigate historical processes at different scales (streets, zip codes, census tracts, wards, municipalities).

p. 123: Suggests that the reason urban historians have shied away from GIS is a “long-standing ambivalence about quantitative analysis among most historians.”

p. 123: Points to Carl Bridenbaugh’s 1960 presidential address at the AHA referring quantitative history as the “bitch goddess.”

p. 123: Points to the critiques of quantitative history, that it was reductionist and positivist, and that the promise of quantitativ ehistory hadn’t been realized through projects like Time on the Cross by Stanley Engerman and Robert Fogel, or Theodore Hershberg’s Philadelphia Social History Project.

p. 123: Cites David Bodenhamer that GIS has not been taken up by historians because (quoting him directly) “The computer, of course, is a technology that does not tolerate ambiguity. . . . Its insistence on precision does not fit the worldview of historians. . . . Given this stance, it is no occident that GIS, the tool initially of engineers and earth scientists, has made few inroads in history.” GIS has no good way of encoding uncertainty, making it more difficult for historians to qualify the arguments/data, show interconnections, or reference sources in an accessible way.

p. 124: She finds that in articles printed between 2002 and 2009 in The Journal of Urban History and the Journal of Planning History very few use maps created in GIS (but do use maps occasionally).

p. 125: Rare also are the incorporation of GIS into manuscripts, the notable exceptions being Colin Gordon’s Mapping Decline (2008) and Jordan Stanger-Ross’s Staying Italian.

p. 125: She’s pointing to her work on W. E. B. Du Bois’ The Philadelphia Negro and GIS to explore how GIS can make contributions to historical scholarship. “Ultimately, GIS will be of interest to urban and planning historians only if it allows them to see history differently.”

p. 125–126: One way GIS helps is by “making explicit the spatial processes they study.” Narrative history allows the description of change over time and space, but that often prejudices temporal patterns over spatial patterns. Using GIS helps explore why geography matters.

p. 126: Linking research methods to spatial processes allows researchers to explore spatial questions or generate new questions about spatial patterns, not just illustrate findings after the fact.

p. 126: Writing about Philadelphia, she notes that by conceptualizing redlining as a spatial process reveals that “only because spatial differentiation developed among racial and income groups and land uses in the early part of the twentieth century could lenders avoid making loans to particular groups with the aid of maps.” GIS helped her calculate the proximity of residential neighborhoods to commercial areas and industry, analyzing racial composition, housing quality, mortgage availability, and the impact of redlines on lending patterns.

p. 126: The value of GIS isn’t just in mapping geographic features, but also “multiple characteristics, or ‘attributes,’ of those locations, transforming reference maps into thematic maps that show how certain conditions or features vary over space.” GIS allows for layering and the creation of multiple maps.

p. 127: Hillier stands her map against Du Bois’ contention that blacks in Philadelphia had limited options about where they could live, crowding into small houses along back streets and alleys but in proximity to wealthy whites they worked for as servants. The GIS analysis differentiates among the black community based on where they were born and the national origin of white neighbors, revealing a level of complexity between race, class, national origin, and housing “only understandable though a map.”

p. 129: “GIS makes it feasible to engage in this exploratory process of mapping, not just map making.”

p. 131: Suggests historians need not think of GIS as quantitative; cites Cope and Elwood’s Qualitative GIS that says GIS is qualitative, noting the nonquantiative origins of GIS in geography, land use planning, census adminstration, and computer science. Qualitative data can be encoded and incorporated—historical maps, photographs, resident perceptions.

p. 131: GIS can also be interpreted as a historical argument.

p. 131: GIS may only reinforce dominant narratives about cities, but they will add more detail and nuance. Points to Gordon’s Mapping Decline, giving more spatial evidence to government, white homeownership, and real estate complexity in St. Louis. Maps may also challenge what we take for granted.

p. 132: “Would a series of comparative spatial-temporal analyses of white flight provide the kind of evidence Robert Beauregard has argued is missing in the dominant narrative about government complicity in urban decline? Could maps be used to develop a more nuanced ‘geography of decline’ that incorporated temporal and spatial patterns across cities and regions?”