By Nora Pehrson
Drawing on chemistry, biology, geology, botany, and ecology, Dave Hsiung is studying the American Revolution and how Americans have interacted with and changed the land ever since. He’s using the concept of metabolism as a way to understand how military actions shaped the environmental landscape of the developing nation, as well as how the natural world affected civilians and soldiers during the War of Independence.
Hsiung is the Charles and Shirley Knox Professor of History at Juniata College and a 2020 Virginia Humanities Fellow in Residence.
We recently sat down to talk about a book manuscript he’s working on, The Military Metabolism of the American Revolution: An Environmental History of the War of Independence.
When most people hear the word “metabolism,” they probably think first about the human body. But in your work, you use the term “military metabolism” to describe the sources of energy that powered the American and British troops during the Revolutionary War.
What does it mean to think about a military as having a metabolism? Can you unpack that term?
Well, it’s a metaphor. If we think about a body, a body needs energy to maintain its basic functions. So when we’re asleep, our heart keeps beating, our lungs keep inflating and deflating, our liver keeps on filtering, and that all takes energy. But then the body needs more energy to go do something. To write this interview, for example, you needed more energy.
There are scholars who look at the metabolisms of societies and cities. A city has a metabolism; it needs energy like electricity to survive, and it creates waste. It struck me that militaries work the same way: armed forces need energy just to exist, and more energy to engage in battle, to move from one camp to another, and so on.
So the concept of a body’s metabolism is a framework for thinking about the energy demands of armed forces and civilian populations. It provides a way to think about military strategy, tactics, and effects on the environment, both short term and long term.
And armies need really high amounts of energy, right?
That’s right. That leads to the next question: how much energy did the army need? I got lured by the kind of quantitative certainty of energy, that it takes so many joules, or calories, or watts, or horsepower, to move X amount of weight Y amount of distance.
If you’re going to march twenty miles a day and you’re an adult male weighing 180 pounds, for example, it will take X amount of calories. Agricultural scientists have said a kilogram of oats provides Y amount of energy. So if I could get some numbers of how many barrels of beef, how many bushels of wheat were available, how many men there were, maybe I could just work the calculator and conclude that they did not have enough energy to march twenty miles. And because the men did march twenty miles, maybe they were then in a depleted state, meaning they were no good when it came time for the battle. So, a quantitative approach like that can really tell you something about the qualitative, more subjective interpretations of a major historical event. By the way, it’s not very easy getting the energy content of all of the foods people ate in 1776!
In your fellowship proposal, you used the term “hybridity” to describe your approach to studying history. What is hybridity, exactly, and how does it relate to the American Revolution?
Basically, it’s the idea that there is no “pure nature.” Even the most remote spot on the earth, where there is no permanent human settlement, still has its temperature raised by human-caused climate change, still has pollutants that get deposited on it. And just as no spot on earth is purely natural, no human society is totally divorced from the natural world and nothing we do can be isolated from our environmental context. Because nature and human societies are hybrids, it makes sense to examine both when trying to understand the American Revolution.
How do you study centuries-old environmental changes?
There isn’t always specific scientific or biological evidence to draw from, so I look at a lot of anecdotes, word-of-mouth recollections and stories, journal entries, and other primary sources. For instance, someone might have written, “Hey, I was at Valley Forge in 1800, about twenty-five years after the army encampment there, and there are all of these new chestnut trees there.” If I can corroborate that statement with other firsthand recollections about chestnut trees in the area, it becomes a clue about the succession of tree species after the Continental Army deforested a huge area in order to build about 1500 huts and cut 10,000 cords of firewood.
While some of the major effects of the American Revolution were civic—we have three branches of government that are supposed to check each other and we have the electoral college—other effects were environmental: the Revolution changed what kinds of trees grew on the hills at Valley Forge.
Could you talk about how this relates to Virginia and why, specifically, you wanted to come and work here?
Virginia plays a major role throughout the Revolution. The most famous Virginian, I would argue, is George Washington, and some of his military ideas, some of his perspectives as a general, are based on his life as a Virginian. For example, he was a land surveyor before the American Revolution.
Also, from the start, Virginia residents influence the activities of the Army, sometimes by helping it—Virginians supplied the Continental Army with ammunition by making homemade saltpeter for gunpowder—and sometimes by resisting it, by refusing to pay wartime increases in taxes for instance. Finally, the last major battle of the war took place just down the road, at Yorktown.
How do you go about doing your research?
I start by asking questions. There are 16,000 soldiers encamped at Valley Forge. What happened? What does that mean? Washington needs all of that firewood: where does he get it from? What does he say about it? Does he mention it in his letters?
Next, start looking at primary and secondary sources. Then, do some writing. Because the instant you start writing, you realize the gaps in what you know. When I started writing a paper about Valley Forge, for instance, I wanted to begin with a dramatic opening vignette. “In the frosty predawn darkness of Monday…” Well, when exactly would dawn be? I had to look that up. Was it frosty? Well, I found that detail in a soldier’s account. But it was only by starting to write that I knew to look for it. So, there’s this constant tension between wanting to learn new information and getting it down in words. Writing is hard!
Yes, it is! What is the best part of being a Virginia Humanities Fellow so far?
It’s time away from my home campus, time to think and write, day after day. Being here at Virginia Humanities, rubbing shoulders with smart, friendly, engaged people who have a wide range of interests and who have depths of knowledge in areas I don’t, that’s really stimulating.
About David Hsiung

David Hsiung grew up outside of Chicago, IL, earned his B.A. from Yale University, and his Ph.D. from the University of Michigan. He is the Charles and Shirley Knox Professor of History at Juniata College in Huntingdon, PA. In 2000 the Carnegie Foundation for the Advancement of Teaching and the Council for Advancement and Support of Education named him ‘Professor of the Year’ for Pennsylvania.