A few weeks ago I was fortunate enough to hear Walter Johnson speak at Georgetown University about his recently published book, River of Dark Dreams: Slavery and Empire in the Cotton Kingdom (Harvard University Press, 2013). It's a marvelous book that has already garnered wide attention, including this very nice roundtable review at The Junto.
Johnson's work has been important in my own thinking, particularly his thoughts on the linkages between capitalism and slavery prior to the Civil War. There's plenty of food for thought on that topic in River of Dark Dreams, although if you read the book expressly for that purpose you will have to be patient to get to that material. That's OK, since Johnson has a lot of important things to say about the history of the Mississippi Valley, and I want to comment briefly on one which caught my eye.
Johnson has a marvelous chapter on steamboats which brings insight into an important point concerning the history of technology. High-pressure engine steamboats dominated the Mississippi. As Johnson writes:
The high-pressure engine was the defining technical feature of the Western steamboat. Whereas the low-pressure engines employed on eastern and European steamboats relied on precise tolerances to ensure the creation of a vacuum, high-pressure engines simply overcame any imprecision in manufacture (which caused leakage) through a vast overemployment of power. (page 93)In the popular imagination, history of technology can look like a string of innovations, each better than the last. But in the case of these Western steamboats, Johnson notes that the technology actually was not improving. The high-pressure steamboats were "less efficient and more prone to explosion," they were "already antiquated at the moment of their increasing employment on the Mississippi." These boats' voracious appetite for wood, in turn, meant that "the deforestation ... of the Mississippi Valley was the condition that made possible the expansion of the steamboat economy." (page 94) These Hummers of the western waters were the dominant form of transit in the region, but their widespread adoption was was not due to better technology -- it was actually worse technology, shoved into overdrive, which made the growth possible.
Through this close examination of the technology, Johnson demonstrates that economic growth and technological improvement don't always go hand in hand, an important reminder for historians.