Atlases of American Religion, Print and Digital
The go-to source for demographic information about American religious history continues to be Gaustad, Barlow, and Dishno's New Historical Atlas of Religion in America. Most recently published in 2001, this oversized, eight-pound volume is stuffed with beautiful, well-thought-out maps that chart the changes of many religions and denominations. The many maps are accompanied by analysis that also makes the book a survey of U.S. religious history. This accomplishment is especially impressive given the difficulty of finding reliable demographic information about American religion, since the Census Bureau has, except for a few years, not been authorized to gather data about religion. You'll have to pay a pretty penny, but the Atlas is well worth having on your reference shelf.
As useful the Atlas is, it is hemmed in on every side by the limitations of print. To give an example, most denominations have maps of their extent only for 1750, 1850, 1890, 1950, and 1990. Undoubtedly the number of maps was constrained by the limits of space and cost for a printed volume. And what I would give not just for the maps in the atlas but for the data that underlies them! Given the data, historians could ask all kinds of questions and make new maps and charts to answer them. In a printed work, the analysis is necessarily static and limited to the author's questions. In a digital work, the analysis can be dynamic, shaped to the user's questions.
You can see some of the potential of digital work in religion in publications about contemporary religion, such as the Pew Forum's dynamic maps in the U.S. Religious Landscape Survey, and the datasets, mostly sociological, that are published at the Association of Religion Data Archives.* Earlier at this blog Mike Pasquier and Chris Cantwell remarked that while religious history has a strong presence online, it has not very often been the subject of digital humanities work. Perhaps we'll see more work of this kind after the THATCamp which will be held at AAR this year.
The New Historical Atlas's new competitor is the Digital Atlas of American Religion, a website released this April. The Digital Atlas is based on work stretching back at least a decade to an earlier version of the online atlas released in 2001, the same year as Gaustad's Atlas. The Digital Atlas lets the user create maps of data that they select themselves, such as number of adherents or adherents as a percentage of the total, number of congregations or congregations as a percentage of the total, and so on. A slider changes which year the map represents. Users can also represent data ways besides maps, including cartograms (maps distorted to represent the value of data), tree maps, pie charts, and motion charts. Perhaps most useful of all, the user can also look at the underlying data to see what the visualizations represent.
The Digital Atlas was produced by The Polis Center at Indiana University-Purdue University Indianapolis, Florida State University and West Virginia University. You can see a list of the scholars who contributed on the website (though I would guess that many more researchers compiled the data), and more information about the project in a press release.
The main limitation of the Digital Atlas is that the data only goes back to 1890 at its furthest extent, and in many cases it goes only as far back as the middle of the twentieth century. This is not a criticism: it really is extraordinarily difficult to gather much religious demographic data—especially data that can be compared across religions—before the nineteenth century and nearly impossible in the colonial era. But perhaps in future iterations of the site the data will go further back. Twentieth century historians can rejoice; nineteenth-century historians can hope.
Digital methods and tools are opening exciting new possibilities for historical research and publication. If the Digital Atlas of American Religion is any indication that bright future includes religious history.
* I have made a very modest attempt at starting to gather this kind of Historical data and analysis transparently, the reasons for which I've started to write about here.