In 1874, Francis Amasa Walker published the first national statistical atlas of its kind anywhere in the world, based on the U.S. Census. (His accomplishment eventually led to his appointment as the president of MIT, in 1881. He held the position for 15 years, until his death.)

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The prize-winning atlas broke new ground in cartographic design and data visualization, with a stunning array of maps and infographics that measured the nation in the aftermath of the Civil War.

Map Showing…the Distribution…of the Constitutional Population

Walker began by mapping the contours of population density, irrespective of state and county boundaries. Notice that each subsequent map identifies population density in blue ink as the base layer, on top of which other variables are mapped.

Detail of the same map

The darker shading indicates progressively higher densities of settlement. The star just east of Cincinnati denotes the “center” of the population at 1870.

Map Showing the Proportion of the Colored to the Aggregate Population

Walker then mapped subgroups to showcase patterns of settlement and migration. Here is the first map of African-Americans after slavery, set against the contours of the general population (in blue ink).

Map Showing the Proportion of the Foreign to the Aggregate Population

This map of immigrants is nearly the mirror image of the one before, illustrating just how few immigrants had settled in the former slave states. For Walker, maps such as this held tremendous promise for fields of geography, social science, economics, and political economy.

Chart Showing the Principal Constituent Elements

This might qualify as the mother of 19th-century infographics. The chart measures state populations according to their racial makeup but also the dynamics of migration in and out of each. See subsequent slides for details.

Walker’s lengthy explanation of the chart

Walker explained that each square reflected the absolute size of that state’s population, while the squares within represented racial groups as well as the movement between states.

Legend and four state boxes

The chart separated each state’s population into three racial groups, then identified the proportion of each born in and outside that particular state. To the right of each square stands a column identifying the proportion of blacks and whites who had left the state. Together, these migrated racial makeup as well as whether that state was growing or declining in population.

Map Showing in Five Degrees of Density the Birth Rate

Here the darker the region, the more fertile the population. Walker was concerned that the native white population failed to maintain expected growth during the 1860s, even after accounting for the monumental casualties of the war.

Legend of birth rate map

Here the darker the region, the more fertile the population. Walker was concerned that the native white population failed to maintain expected growth during the 1860s, even after accounting for the monumental casualties of the war.

Detail of map of birth rate

Here Walker was particularly concerned about the slow rate of native reproduction in cities, which confirmed his sense that urbanization was a dangerous trend for the nation.

Map of Predominating Sex

On this map, shading indicates areas where men outnumbered women, which is particularly evident west of the Appalachian Range. Notice the opposite ratio in the southeast, where women almost uniformly outnumbered men.

Detail of map of predominating sex

In the sparsely settled areas of the Midwestern frontier, men clearly outnumbered women. A map of these two variables allowed Walker to speculate about migration and demography.


John Snow was just one of many who used maps to investigate the sources of epidemics in the 19th century. Walker mapped the incidence of consumption and other diseases in the hopes of identifying patterns--and by extension the source--of contagion.

Detail of consumption map

Walker’s technique of layering data allowed him to speculate on the potential relationship of population density to the outbreak of consumption (tuberculosis).

Chart of Gainful Occupations…and also as Attending School

Walker designed several of these infographics to measure American moral fiber, including church attendance and work ethic. The shaded border identifies the rates of idleness (those neither in school nor working). Note that according to the census, women already constituted 50% of those attending schools across the nation.

Detail of Gainful Occupations chart

Notice that the number of farmers had already dramatically declined in the Northeast relative to the Midwest and South.

Map Showing the Illiteracy of the Population

Here Walker used shading to identify higher rates of illiteracy, mapped against the density of the population in blue ink. He did this to posit a relationship between population density and rates of illiteracy, though there is no apparent connection on this map.

Detail of Illiteracy

Instead, illiteracy appears to be highest in the areas that had correspondingly high slave populations before the Civil War.

Chart Showing the Aggregate Number of Idiots

This is one of several graphics Walker designed with Frederick Wines, a leading criminologist of the era. Walker was not satisfied with simply identifying the number in 1870, but measured it against the prior census to investigate rates of change.

Detail of Idiot Chart

Notice that he groups the states according to geographical region, and identifies rates of idiocy among the native born white, colored, and foreign populations.

Chart Showing the Aggregate Number of Insane

Like the previous chart of idiocy, here Walker measures the rates of insanity by sex, geography, ethnicity, and race, and asks about the rate of increase relative to the Census of 1860.

Detail of Insanity Chart

Walker attempted to measure the spatial and racial distribution of everything from the incidence of disease and illiteracy to public debt and migration. His motives were complex, but he used infographics and maps to seek patterns that might otherwise remain hidden or lost.

How A Civil War Vet Invented The American Infographic

As the superintendent of the U.S. Census, Francis Amasa Walker sought to map patterns that might otherwise have remained hidden or lost. In doing so, he paved the way for the modern infographic, writes historian Susan Schulten.

The 2012 election brought us a deluge of maps. They predicted the breakdown of the electoral and popular vote, analyzed the size of each party’s lead, explained the shift from past elections, and charted the influence of ethnicity, economic condition, and geography. Data maps—and their cousins, infographics—have become routine, used for everything from urban planning and research to marketing and economic speculation.

Click to enlarge.

This explosion of population mapping owes much to the extraordinary geovisualization techniques of Francis Amasa Walker, a highly decorated Union soldier in the American Civil War. After the war ended, Walker found himself casting about. He taught languages for a few years and dabbled in journalism before his family connections brought him a job in the Bureau of Statistics. Walker had a knack for working with data, and at the tender age of 29 was appointed as superintendent of the Census of 1870. This position gave him the chance to think of the census not just as a tool of enumeration and political apportionment (its original purpose), but as an instrument of research and development. Think of Walker as an early advocate of data mining for the nation. To properly exploit the census, however, he had to make sense of the data, and this led him to experiment with maps and infographics.

In 1872, he issued the first of several groundbreaking attempts to map the American population through the census. But instead of using preexisting units—such as county or state divisions—he took the more labor-intensive step of mapping the population according to its actual contours. By doing this, he moved closer to seeing the population as it existed in space, irrespective of political boundaries. Take a look at his map of the general population, which identifies six classes of density.

He then realized that this technique could be used to map various subgroups—immigrants, African-Americans—in addition to characteristics, such as wealth, illiteracy, or the incidence of disease. Armed with his experimental maps, Walker excitedly asked Congress to support a much more ambitious effort to comprehensively map and chart the census in an atlas. The maps did the trick, and Congress appropriated $25,000 for Walker to create the first national statistical atlas in the history of the world.

Then, after his project was funded, Walker began to think about maps in even more unconventional and adventurous ways. The first maps he made in 1872 (like that above) focused on a single class of information, such as population density, wealth, or illiteracy. By 1873, he realized that a far more complex—but perhaps useful—picture of the national population could be created by integrating two classes of data onto a single map. Take a look at his two maps of wealth, the first from 1872 and the second made soon thereafter.

The map at left identifies wealth per capita, while the map at right integrates population density.

The map at left shows the distribution of wealth in absolute space. It tells us that there is slightly higher per capita wealth in certain locations, such as the North relative to the South. But the map at right represents a fundamental departure: It maps not just the distribution of wealth in orange but also population density with blue contour lines and numbers (identifying areas of 2–18 per square mile, 18–45 per square mile, etc.). This second map opened up the radical possibility of connecting two types of information in space, such as the relation of wealth to population density. Walker used this same technique to map illiteracy, disease, the birth rate, public debt, and ethnic subgroups, each time incorporating the blue ink of population density so that the dynamics of the population could be seen.

With this quiet experiment, Walker audaciously inaugurated an entirely new purpose for the map, one that was analytical as well as descriptive. He was not the only one engaged in such work and, in fact, was deeply influenced by the examples brought from Europe by talented German immigrant mapmakers and lithographers. With this transatlantic collaboration, he conceptualized the map as not just a representation of data but a tool to uncover patterns and relationships. In other words, his maps were designed not just to illustrate the data but to transform that data into knowledge. Consider that without the map, these spatial patterns would be lost.

Here are two details from his maps of the colored population (on the left) and the foreign (on the right). The maps are nearly mirror images, suggesting patterns of migration and settlement that had much to do with the legacy of slave labor and the corresponding hostility to immigration. For Walker, the possibilities for mapping data such as this were nearly limitless.

A detail from Walker’s map of the colored population (left) and the foreign population (right).

This, of course, is the intellectual conceit behind our complex use of maps today, and especially behind Geographic Information Systems (GIS), where data is arranged spatially. But in the late 19th century, this was entirely new—so new that when Walker showed the maps to his colleagues (some of the most educated men in America), they were slow to grasp the potential of this new tool. He had to train them to think about a map in new terms.

Walker’s own politics were clear: The trouble with America was excessive urbanization and immigration. Notice in the slide show how many of the maps and charts identify and measure the foreign population. Such maps can be—and probably always will be—used to manipulate data to suit particular ends and political agendas. But Walker’s audacious experiment in the 1870s laid the foundation for the explosion of maps and infographics thereafter. As president of MIT in the 1880s, he insisted that students be trained not just in science and technology, but also the graphic visualization of data. For Walker, the communication of information was as important as the information itself.

[Images courtesy of David Rumsey Map Collection and Library of Congress]

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