There are some maps that, at first look (or second, or one-hundredth), seem to offer more questions than answers. It can surely be said that the map of nationalities in New York City, part of a series of maps from the Tenement House Committee of 1894, is one such curiosity. Looking closer at its historical context, however, can help us understand its impact and what it tells us about a city in transformation.

Map No. 2 of The Tenement-House Committee maps. Map by Frederick E. Pierce, 1895. Geography and Map Division.

New York City was growing rapidly in the latter half of the 19th century, with large numbers of mostly poor European immigrants settling into tenement buildings, particularly in the Lower East Side of Manhattan. Tenements of the time were generally repurposed single-family homes or purpose-built structures renting to multiple families on each floor. These buildings, of which there were over 15,000 in New York by the end of the Civil War, were notorious for their squalid conditions: extreme overcrowding, little to no natural light or fresh air, mounting trash and grime, and few fire escapes. Diseases like cholera and tuberculosis were rampant in these dense, unsanitary buildings.

Efforts at tenement reform were largely ineffectual by 1890, when journalist Jacob Riis published How the Other Half Lives, an uncompromising book of photographs and reports of tenement life that brought widespread attention to the urban slums and spurred calls for action. The Library of Congress, in partnership with the Museum of the City of New York, chronicled Riis’s life and work in the Jacob Riis: Revealing “How the Other Half Lives” exhibit in 2016.

Five cents a spot – unauthorized immigration lodgings in a Bayard Street tenement [New York]. Photograph by Jacob A. Riis, 1890. Prints and Photographs Division.

In 1894, the New York State legislature created the Tenement House Committee, which was tasked with examining tenement housing in New York City and the effects of these crowded and unsanitary living conditions on their residents. The following year, the committee delivered to the legislature its comprehensive report, detailing the deplorable living conditions and recommending a wide range of reforms.

Frederick E. Pierce produced six maps for the report, four of which were soon published in Harper’s Weekly, reflecting the public interest in the issue, particularly among social reformers. In each map, north is roughly oriented to the right, so as to show Manhattan in a landscape orientation. Most of Pierce’s maps are fairly straightforward, including two that compare population density in the city from 1860 to 1890, using census data. The maps clearly show rising population density concentrated in the Lower East Side.

Detail of Map No. 3 of The Tenement-House Committee maps. Map by Frederick E. Pierce, 1895. Geography and Map Division.

Detail of Map No. 6 of The Tenement-House Committee maps. Map by Frederick E. Pierce, 1895. Geography and Map Division.

Pierce’s map of nationalities, however, is a more memorable, if confounding, centerpiece. Aiming to convey diversity among immigrant communities in New York, the map depicts the proportion of major “nationalities” in each sanitary district of the city. The result is a dizzying array of zigzag stripes and scattered points. As Pierce writes in his explanatory notes accompanying the Harper’s Weekly publication, the original map was produced in color and adapted to black and white for publication, but the reproduction “is almost as effective and quite as illustrative as the original.” Despite Pierce’s confidence, perhaps the average reader could be forgiven if they find the map to be more difficult to parse. In fact, the map seems to resemble more closely the dazzle camouflage, a design aimed at confusing the observer, used on British and American warships in the first half of the twentieth century.

Detail of Map No. 2 of The Tenement-House Committee maps. Map by Frederick E. Pierce, 1895. Geography and Map Division.

The methodology behind the nationalities map raises more fundamental concerns. Besides the ambiguities of “nationality” as a defined census figure altogether, Pierce writes that “the Scotch, English, Welsh, Scandinavian, and Canadians…being in small numbers, and perhaps less foreign than the others, were disregarded.” Furthermore, only nationalities “making up two-thirds of the population of any district” were mapped, thereby minimizing the true ethnic diversity of many New York neighborhoods. Even African Americans are mapped separately from “natives” (in this context, meaning white Americans born in the United States). The complicated methods behind the mapping of this data point to the racial biases and prejudices surrounding the idea of “foreignness” and what it meant to be an American at this time.

Despite its puzzling cartographic design and flawed methods, the map reached a wide audience through its publication in Harper’s Weekly and was a breakthrough moment for reformers. Several years later, the New York State Tenement House Act of 1901, one of many reforms ushered in during the Progressive Era, banned windowless interior living spaces and mandated that new tenement buildings have indoor bathrooms, improved lighting, fire safeguards, and proper air ventilation.

Family in poverty gap, N.Y.C. tenement room. Photo by Jacob A. Riis, 1889. Prints and Photographs Division.

The Tenement House Committee maps reflect not only a city facing crises of public health and overcrowding in the tenements, but also deeper fears among certain segments of society of immigration and cultural change. The incoherence of the nationalities map’s design doesn’t blunt this point. As described by Art M. Blake in How New York Became America, 1890-1924,

the power of the maps…resides not in any ‘truth’ index, any correspondence between a cartographic representation and reality, but rather in the appearance of factuality, the look of scientific truth.

While the nationalities map itself may not get much clearer to decipher on repeated examinations, the broader effect of the erratic design is what made the impact at the time and, alongside its historical context, why it still resonates today.