In this fluidly written and beautifully illustrated work, Jason Hansen traces the history of ethnographic cartography in the German lands between the early nineteenth and early twentieth centuries, demonstrating how these projections of national space gained increasing legitimacy. Whereas early nineteenth-century efforts to draw the ethnic frontiers of the German people in cartographic form generated little interest, the project of representing ethnic borderlands would capture both the academic and public imagination by the late nineteenth century. This shift, Hansen claims, resulted from two main factors. First, it drew on the mid-nineteenth-century rise of more exact census data collected by states that were moving from impressionistic assessments by local notables to household surveys. Second, it benefitted from the emergence of more precise printing technologies, such as lithography and the use of chemical dyes. These changes permitted the production of maps that could assert scientific accuracy, lending authority—notwithstanding the sticky problem of assessing an individual's ethnic identity—to claims that they represented reality. Gone were hand-colored maps produced from worn copper plates, each with its own subtle quirks. By 1900, ethnographic maps backed by statistical data presented clearly-demarcated boundaries with bold color contrasts among nationalities, along with apparently accurate detail down to the household level.

The production of these authoritative and colorful maps, and their wider circulation in the late nineteenth century as a result of improvements in printing technology, helped produce a spatial shift in nationalist discourse. Scholars had relatively little interest in investigating the German nation's fuzzy ethnic frontiers in the early nineteenth century, but the increasingly detailed data about ethnicity—derived from questions about language use that liberal nationalists had lobbied to include in censuses in the mid-nineteenth century—produced a raft of studies about the gains and losses made by particular nationalities in particular borderlands. Now that maps no longer identified the nation's ethnic frontiers as vague liminal zones but rather as crisply defined districts with precisely enumerated ethnic groups, nationalists could move from using maps as evidence of national unity to diagnosing instead what they regarded as national ills—such as the rise of non-German-speaking groups within what they identified as deutscher Volksboden. Such assessments from late-nineteenth-century radical nationalists allowed them to propose public and private measures to redress the ethnic threats they perceived in the borderlands.

This preoccupation with the spatial representation of ethnicity was by no means unique to radical German nationalism. Indeed, Hansen states that radical German nationalists continued to approach cartography in the same manner established by their liberal forbearers, i.e., by using what they regarded as scientific data to represent the nation in visual form. Alongside their shared confidence in the scientific foundations of their enterprise, both liberal and radical nationalists fundamentally believed in the desirability of congruence between the nation and the state. The main difference between them, Hansen suggests, was the radicals' willingness to intervene in shaping the nation through government action: this contrasted with the liberals' tolerance of ethnic minorities and, one might add, their confidence in the gradual assimilation of minorities through social forces.

At the same time, Hansen argues, German ethnic cartography differed little from the forms practiced by other Europeans. He stresses the general agreement between European statisticians and cartographers at the International Statistical Conferences held between 1853 and 1872, which sought to standardize approaches to census data and its representation. Moreover, he notes that all the major powers at Versailles, whose leaders sought to reshape Europe to conform better to perceived ethnic realities on the ground, embraced the ideal of accurately mapping ethnic relations. They, too, subscribed to the liberal goal of a neat correspondence between nation and state.

Hansen's claims about the continuities between liberal and radical nationalism, as well as about a common European faith in ethnographic cartography, are certainly intriguing, but they would have been strengthened by additional evidence. Greater comparison of the cartographic traditions of other European countries with the German case certainly would have been helpful, too. For example, when did the French—who have a reputation for supporting civic, not ethnic, nationalism—embrace ethnographic maps as a useful tool: in the wake of the loss of Alsace-Lorraine, at Versailles in 1919, or at some other point? Hansen devotes a paragraph in the conclusion to considering the radicalization of German cartography in the 1920s, as it shifted from an emphasis on ethnicity to representing space in a way that corresponded to the Nazis' growing interest in an imperial Raum. More discussion of this transformation would have highlighted the continuities between liberal and radical nationalist approaches, as well as clarified the relationship between the radical nationalism of the pre-1914 era and its Nazi successor. Despite these limitations, Hansen's book engagingly portrays the changing nature of ethnographic cartography in the nineteenth century, demonstrating clearly why maps became a major preoccupation for German nationalists by the early twentieth century.