Side-By-Side Comparisons

I said my next post would be methodological: how I carried out the project, why I made choices I did, and so on. But in the meantime I want to post this web application that allows you to make side-by-side comparisons of the map of slaving voyages.

Atlantic Slave Trade Voyages, 1751-1795

The first aspect of the ACLS project that I am publishing relates to the Atlantic slave trade.

I decided to share it first because of its close relationship to the online digital humanities project I used the most for my research on the role of people of African origin in establishing open-range cattle ranching in the Americas (see my 2012 book, Black Ranching Frontiers), namely the Trans-Atlantic Slave Trade Database. That digital humanities project produces summary and customizable tables, statistics, and graphs regarding the transport of some 12.5 million enslaved Africans across the Atlantic Ocean over the sixteenth through nineteenth centuries, but it produces maps only of the embarkation and disembarkation ports for the some 35,000 voyages.

In contrast to the the Trans-Atlantic Slave Trade Database, the GIS posted below produces maps of the routes of forty-eight slaving voyages during the second half of the eighteenth century. The daily, noontime vessel position and other data come from the Climatological Database for the World's Oceans, 1750-1850 (CLIWOC), a project that assembled maritime weather observations from logbooks in archives in Britain, the Netherlands, and Spain. Forty-six of the forty-eight voyages are Dutch and two British, most of them transporting enslaved people across the Atlantic from Africa to Suriname and the Caribbean. Forty-four of the voyages also appear in the Trans-Atlantic Slave Trade Database, and clicking any of their daily position markers pops up a box with a link ("More info") to the relevant record in that database (the other four voyages concern vessels that carried slaves on voyages that were not trans-Atlantic). The box also contains date and cargo information as well as, in some cases, an image of the vessel. Clicking the route line of a voyage brings up a box with the vessel name and, in some cases, a description of arrivals, departures, and cargoes from the shipping news sections of newspapers. You can also click on place markers for the archives in Europe that preserve the logbooks, ports along the African coast and in the Caribbean, and so on to bring up images and links to further information about those places.

The GIS thereby facilitates novel visualizations of the slave trade, allowing users to better appreciate the horror of this monumental forced migration. For example, the map layers that show the patterns of death among the enslaved and disposal of their corpses overboard during the Middle Passage from Africa to the Americas help to visualize that aspect of the slave trade. One uses proportional point symbols to convey the number of deaths on a particular day at a particular position in the Atlantic. Another displays the density of deaths and disposals across the entire Middle Passage.

I hope you enjoy the GIS (despite the heinous topic), provide feedback, suggest collaborations, and feel free to use the data and programming to produce non-commercial derivative products.You can modify the GIS and save a new version by opening it in either the  free ArcGIS Online map viewer or in ArcMap 10 if you have it installed on your computer. Simply click on the "View Larger Map" link just below the map.

The GIS and blog are © 2013 but open source and licensed through the Creative Commons as attribution-noncommercial 3.0. The logbook data that the GIS maps ultimately derive from archival transcriptions carried out in British and Dutch archives by the CLIWOC project team members, who state that the “aim of the project is to produce and make freely available for the scientific community the world’s first daily oceanic climatological database” (www.ucm.es/info/cliwoc/intro.htm). The CLIWOC 2.1 MS Access database, which you can download from the CLIWOC website, includes fields that identify the archive, document number, and the CLIWOC team member who transcribed the logbook for each of the voyages. Anyone is therefore free to use this GIS as a basis for new, non-commercial, scholarly and creative works as long as each such GIS, website, and/or publication contains a statement that acknowledges Andrew Sluyter as this GIS's creator and CLIWOC as the source of the data.

My next post will be methodological: how I carried out the project, why I made choices I did, and so on. Other GIS postings will follow, each related to another aspect of the project.

View Larger Map

Purpose of this blog

I have created this blog to share the results of a project called an Internet-Based Geographic Information System (GIS) of Nineteenth-Century Atlantic Commodity Networks that I have been working on while a 2012-13 Digital Innovation Fellow of the American Council of Learned Societies.

Abstract. This project initiates an Internet-based GIS of nineteenth-century Atlantic commodity networks. Data come from logbooks of vessels and include daily position, cargo, and crew information. All data are in hand, derived from previous archival work and the public-domain CLIWOC database (Climatological Database for the World’s Oceans). In contrast to existing databases such as the Trans-Atlantic Slave Trade Database, which emphasize temporal analysis, the use of a GIS that associates every data point with a geographic location allows users to employ web browsers to spatially analyze and visualize the routes of voyages (rather than only embarkation and disembarkation ports); maritime literature related to routes; volumes of trade by route and season; and other information.

As various aspects of the project come to fruition over the next few months, I will post them here.

All materials that I post, including Web maps and applications, are © 2013 by Andrew Sluyter but open source and licensed through the Creative Commons as attribution-noncommercial 3.0, which allows others to use the data and programming to produce non-commercial derivative products.

For more information on me, my current position, other projects, courses, service, articles, and books please visit http://lsu.academia.edu/AndrewSluyter and http://en.wikipedia.org/wiki/Andrew_Sluyter.

OVERVIEW OF THE PROJECT

The interdisciplinary field of Atlantic Studies has delivered many new insights and matured to the point of self-reflection and -critique. Its scholarly monographs transcend regionalism to emphasize the interconnections among Europe, North America, Latin America, the Caribbean, and Africa; bring long-ignored actors to life; and conceptually transform the Atlantic into a dynamic space of flows rather than a dead space of separation. Its collaborative efforts have established Web-based databases such as the Trans-Atlantic Slave Trade Database (TSTD) that will stimulate new research for decades.

The goal of this project is to initiate another such Web-based database, stimulated by my research on the logbooks of the merchant vessels that participated in an Atlantic commodity network (Sluyter 2010). Unlike most other such efforts in the humanities, this database was developed as a Geographic Information System (GIS) and thereby is intrinsically spatial in order to engage “geographically integrated history” (Owens 2007). It focuses on mapping the routes of vessels between about 1750 and 1900 that carried cargos of coffee, sugar, spices, gold, and many other products as well as enslaved Africans between Europe, Africa, the Caribbean, South America, North America, and Asia.

Such analysis and visualization of Atlantic shipping networks has intellectual roots in the Annales School and present-day parallels in the Climatological Database for the World's Oceans, 1750-1850 (CLIWOC), a database that climatologists have constructed using the weather observations found in historic logbooks. A massive Annales project of the 1950s reconstructed Spanish shipping of the sixteenth- and seventeenth-century Atlantic to produce insights about the routes, timing, and other characteristics of the annual fleets that still inform our understanding of colonial Latin America. CLIWOC uses the Web to make public its database of daily vessel positions and weather observations from more than 3,000 Spanish, English, French, and Dutch logbooks dating to the 1700-1800s. Its purpose is to reconstruct historic climate for the era before establishment of widespread weather stations and climate satellites rather than analyze Atlantic shipping and commodity networks, but application of CLIWOC methods to the intellectual ambitions of the Annales School first suggested this project.

The inclusion of about 75 voyages drawn from CLIWOC and my own research on Catalan logbooks as well as nineteenth-century historic hurricane tracks from the National Oceanic and Atmospheric Administration demonstrates the potential for such a Web-based GIS approach to understanding the relationships among different commodity networks and social and environmental processes. It also facilitates enhancing the sophistication of related analyses and visualizations; serves the GIS on the Web to allow other scholars to use it to answer questions related to their own intellectual interests and to submit additional data for inclusion; maps the actual routes of some of the slave voyages included in TSTD rather than only the embarkation and disembarkation ports; and builds a teaching component into the project website that can stimulate and facilitate other humanities scholars to initiate more such Web-based GIS databases for a broader range of topics.

Such Web-based databases are inherently scalable. Scaling up would involve additional data contributed by users, as they have done for the TSTD. With the inclusion of additional voyages, users will be able to, for example, generate animated visualizations of the actual routes of specific vessels in relation to particular hurricane tracks; graph the relative volumes of trade along different routes in different seasons for a particular commodity; and link to other data, such as maritime art and literature associated with particular shipping lanes, or even particular vessels and voyages.

To facilitate scaling up, this blog includes extensive information on the data used and the methods to build the Web-based GIS.

Selected References

1. Bailyn, Bernard, Atlantic History: Concept and Contours (Cambridge, Massachusetts: Harvard University Press, 2005).
2. Boelhower, William, “I’ll Teach You How To Flow”: On Figuring Out Atlantic Studies, Atlantic Studies 1 (2001): 28-48.
3. Carney, Judith A., and Richard N. Rosomoff, In the Shadow of Slavery: Africa’s Botanical Legacy in the Atlantic World (Berkeley: University of California Press, 2009).
4. Elliott, John H., Empires of the Atlantic World: Britain and Spain in America 1492-1830 (New Haven: Yale University Press, 2006).
5. Eltis, David, The Rise of African Slavery in the Americas (Cambridge: Cambridge University Press, 2000)
6. Eltis, David and David Richardson, An Atlas of the Transatlantic Slave Trade (New Haven: Yale University Press, 2010).
7. Green, Jack and Philip Morgan, Atlantic History: A Critical Appraisal (Oxford: Oxford University Press, 2008).
8. Scott. Rebecca J., Public rights and private commerce: a nineteenth-century Atlantic creole itinerary, Current Anthropology 48 (2007): 237-256.
9. Sluyter, Andrew, The Hispanic Atlantic’s tasajo trail, Latin American Research Review 45 (2010): 98-120.
10. Sluyter, Andrew, Black Ranching Frontiers: African Cattle Herders in the Atlantic World, 1500-1900 (New Haven: Yale University Press, 2012).
11. Topik, Steven, Carlos Marichal, and Zephyr Frank, eds., From Silver to Cocaine: Latin American Commodity Chains and the Building of the World Economy, 1500-2000 (Durham, North Carolina: Duke University Press, 2006).