A great rarity of thematic mapmaking: a Charles Joseph Minard “flow map” tracking the impact of the American Civil War on the global cotton trade.

Minard was one of the great 19^th-century innovators in what Edward Tufte has called the “visual display of quantitative information.” Over the course of a quarter century he produced dozens of stunning maps addressing different elements of economic geography, usually involving the movement of goods and/or people through space. Offered here is one of his relatively few maps to depict an American subject, and a vital one at that: the impact of the Confederacy’s “cotton diplomacy,” its attempt to use an embargo on cotton exports to force intervention by European powers in the Civil War.

Charles Joseph Minard (1781-1870)
Charles Minard’s career may be viewed as having two distinct phases, his decades as a prominent civil engineer clearly laying the groundwork for his second act as a “visual engineer.” (Friendly, p. 33) Born in Dijon in 1781, he received a top-drawer education in mathematics, science and engineering, first at the École Polytechnique and then at the École Nationale des Ponts et Chaussées, the training ground for the engineers responsible for building and maintaining France’s infrastructure of ports, roads, canals and railroads. He spent the better part of a half century with the Ponts et Chaussées, the first 25 or so working primarily on canals and related projects. In 1830 he was named superintendent at the École Nationale, in which role he served—while also performing teaching duties—for the next six years. During this time he developed a deep interest in railroads and traveled widely to develop material for his curriculum.

In 1839 he was promoted to “divisional inspector” within the Ponts et Chaussées, and in 1842 he was freed from teaching, but the required travel was a burden due to his ill health. Rather than leaving the service, however, in 1846 he received an appointment as one of seven Inspectors General of the Ponts Et Chausée and a member of its governing council, which directed all work of the department. He finally left the department in 1851 after reaching the mandatory retirement age of 70.

In March 1845, while still at the Ponts et Chaussées, Minard had published his first thematic map, “a relatively crudely drawn flow map of the movement of travellers in the region from Dijon to Mulhouse” (Robinson, p. 98). In all he is credited with dozens of such maps depicting statistical data in graphic form, the vast majority produced in the nearly two decades after his “retirement,” usually at a rate of several per year. Most bear a title beginning with the phrase “Carte Figurative et Approximative,” roughly, “Figurative and Approximate Map,” a clear signal that their intent was thematic rather than purely geographic.

“His concern for the “accuracy” of his data is shown by the fact that he was as accurate as he could be with respect to the system of portrayal, that is, the width of a flow line on a Minard map is always strictly proportional to the magnitude it represents. But on the same map he would strongly resist the tendency of the tyranny of precise geographical position to detract from the essential communication of his chosen theme. Accordingly, he revised coastlines, paid little attention to projections, and forced the scales of the graphical features on his maps to fit the data being portrayed rather than vice versa…” (Robinson, pp. 95-96)

Many of these Cartes Figurative et Approximative are what Robinson calls “flow maps,” in which “the width of a flow line… is always strictly proportional to the magnitude it represents.” (Robinson, p. 95) It is worth noting that, while Minard is by far the best-known maker of such maps, the technique was pioneered by one Henry Drury Harness, on an 1837 map of Ireland. Minard’s maps covered a huge range of subjects, though almost all related in some manner to the movement of goods and/or people: the export of coal from England; shipments of French wine by sea; numbers of rail passengers across Europe; imports of cotton and linen to Europe before, during and after the Civil War; and of course his famed maps of the campaigns of Hannibal and Napoleon.

Minard’s influence in France was such that “from about 1850-1860, all Ministers of Public Works in France had their portraits painted with one of Minard’s creations in the background.” (Friendly, p. 33) Though Robinson estimates that his maps “were published in editions of a few hundred to perhaps a thousand copies and apparently were widely used in official circles,” they are today sought-after rarities on the antiquarian market, particularly those with strong American content, as the example offered here.

The American Civil War and cotton diplomacy
By the outbreak of the Civil War the American South was by far the most important producer of cotton, the key ingredient in the world’s single most important industry. One author, for example, cites estimates that it supported the livelihood of 20 and 25% of all people in Britain, attracted 10% of all British capital, and yielded 50% of all British exports. (Beckert, p. 1408) In August 1861 the Confederacy sought to exploit this fact by placing an embargo on cotton exports, with the goal of compelling cotton-dependent European countries—England and France in particular—to recognize the Confederacy and even intervene to break the Union blockade of its ports. What the Confederacy failed to take into account was the surplus of cotton in European warehouses (nearly 600,000 bales!) and, above all, the flexibility of British capitalists and Indian and Egyptian growers, who together combined to rapidly develop alternative sources of production.

“Especially for [European] merchants, but also for some manufacturers and even a few workers, the desire to secure cotton at first made them powerful advocates for the cause of the Confederacy. Yet their ability to reshape the cotton industry by giving India, Egypt, and other places important new roles moved them increasingly into the Union camp, persuading them that emancipation and cotton production might not be mutually exclusive.” (Beckert, p. 1416)

This remarkable map by Minard documents the early effects of the Confederacy’s cotton diplomacy and hints strongly at the strategy’s ultimate failure.

Minard’s flow map of Civil War-era cotton exports
The image features two identical base maps of North and South America, Europe and Africa, that on the left representing the year 1858 and that on the right 1861. In the United States the seceded states are named and shown in outline—with the odd exceptions of Arkansas, North Carolina, Tennessee and Virginia! Across the Atlantic some 17 cities somehow involved in the cotton trade are identified, from Alexandria to Barcelona to St. Petersburg. As usual on Minard’s flow maps, coast lines have been distorted as necessary to accommodate the heavy “streams” used to represent economic data, in this case volumes of cotton and linen exported and imported. Minard uses color coding to indicate country of origin: blue for American, yellow for Indian, brown for Egyptian, gray for Brazilian, and pink for re-exports from England to the Continent.

Even a cursory comparison of the two maps suggests that something unusual was going on: While imports of American cotton and linen appeared to hold steady from 1858 to 1861, imports from India had increased threefold. The histogram at upper left helps the viewer make sense of this apparent anomaly. It charts thirty years of three key dimensions of the cotton and linen trade: American exports (blue), Indian exports (yellow), and British imports (brown). A smaller, uncolored histogram at far upper left tracks French imports of the same. The message is clear: British (and, to a much lesser degree, French) demand for the raw materials had soared, notably after 1850, and American producers had responded accordingly, with a particularly striking leap in harvest size from ca. 600,000 tons in 1857 to more than 900,000 in 1859. In 1860, however, with the secession crisis brewing, this figure plummeted to 650,000, dropped further to 548,000 in 1861 (as shown on the right-hand map), and would all but collapse in 1862 under the combined pressure of the Confederate export embargo and the Union blockade of southern ports. As shown on the right-hand map, by 1861 Indian producers had ramped up production and exports to respond to the shortfall. In his explanatory notes above the maps, Minard observes:

“It was said in England in 1861 that the cotton factories were threatened with a next meeting by default of raw materials; fortunately the disaster was partly averted by a help on which we had scarcely counted, and which we were far from believing as powerful and above all as quick. This relief, which my map shows to me, is the considerable increase in the importation of cotton from India. In 1861 England received 173,000 tons, twice the average of the previous seven years and about two-fifths of what it uses annually.”

This map was originally owned by railway engineer François Prosper Jacqmin (1820-1889). He worked for the Paris and Eastern Railway Companies, before becoming a professor at the École des Ponts et Chaussées in 1864.

During the course of the Civil War Minard published additional maps tracking the rapid evolution of the cotton trade, in particular the collapse of Confederate exports and the rise of Indian and Egyptian producers, including this map contrasting the years 1858, 1864 and 1865.

Rarity and references
Rare Book Hub lists no examples as having appeared on the market, though one was sold by the firm of Daniel Crouch Rare Books in the past year as part of a large Minard collection (Catalog XV, #12). Though Minard was prolific, all of his works are extremely rare. Rare Book Hub lists only 11 books and maps as having appeared for sale, none with American content, all sold between 2003 and 2014.

Robinson, Arthur, “The thematic maps of Charles Joseph Minard,” Imago Mundi, vol. XXI (1967), #30. Rumsey #10135.  As of February 2018 OCLC lists impressions only at the Bibliotheque nationale de France and the Library of Congress.

See the Robinson article for excellent background on the life and work of Minard, as well as Michael Friendly’s “Visions and Re-Visions of Charles Joseph Minard,” Journal of Educational and Behavioral Statistics vol. 27 no. 1 (Spring 2002), pp. 31-51. For a much briefer, more popular treatment, see Betsy Mason, “The Underappreciated Man Behind the Best Graphic Ever Produced,” National Geographic web site, March 16, 2017. That article also provides a link to a short-but-sweet Youtube video describing Minard’s cotton maps. For background on “cotton diplomacy” during the Civil War, see Beckert, Sven, “Emancipation and empire: Reconstructing in worldwide web of cotton production in the age of the American Civil War,” American Historical Review 109(5): 1405-1438.

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