Horses at Work is a sprawling account of two species sharing a common destiny. Expect no tight thesis, but it’s the story that counts. Ann Norton Greene leads us on a grand tour through the streets and roads, the railroads and waterways, the farms and factories, and the grisly battlefields of the 19th century. The core of her argument is that while steam engines were the backbone of the Industrial Revolution, they required, because of their limited mobility, millions of horses as a complementary power supply. Around this idea she weaves other strands: that energy use shapes ­landscapes—­material, cultural, political, ­social—­and that our energy sources and technologies are determined not just by inexorable material progress but by our culture, our minds, as ­well.

About 1800, with industry rising, Americans were seeking a mobile power supply. The ox was popular, but America chose the horse, mainly for its speed and consequent versatility. Greene launches her narrative with a discussion of physiology and anatomy, and the physics of har­nessing, which gets too technical for her purpose and contains puzzling and misleading explana­tions. Carry on, reader! She recovers, and con­ducts us through the landscape taking shape along the many arteries of the newly developing transportation ­system.

The bustle and hum must have been exciting: freight wagons pulled by teams of six or eight horses, traveling in groups of up to 30; eight thousand horses pulling passengers and freight along the 363-mile Erie Canal; a thousand weekly arrivals and departures by stagecoach in Philadelphia. In 1860, travelers going from Washington, D.C., to New York City began by ­horse-­drawn vehicle, transferred to a train, to a ­horse-­drawn streetcar, to another train, to a ­horse-­drawn vehicle again, to the ferry ­boat—­and that only got them as far as the Susquehanna River!

The Civil War, “the first war of industrialized animal power,” brought a colossal need for horses. In 1861 alone, the Quartermaster Department purchased 194,000 horses and mules. Keeping the Union army supplied with equines, and hundreds of thousands of tons of forage and grain, and millions of iron horseshoes, fell to highly efficient Quartermaster General Mont­gomery Meigs, a desk-bound soldier who lec­tured General William Rosecrans on the care and judicious use of horses and demonstrated to a complaining George McClellan, always tricky with the numbers, that he had received 10 times as many horses as he was reporting. The war ground up horses as it ground up men. One officer folded horses and men into the same casualty ­report.

Industry and industrialized agriculture could be hard on horses too. Especially grueling were the stationary units whose tramping horses turned the gears of power machines to do almost anything. “On the treadmill” was not a metaphor. Cities ran on horse power. In 1872, an epidemic of equine influenza brought Philadelphia to a standstill. They couldn’t even get beer to the saloons!

New York and Chicago each averaged nearly 500 horses per square mile by 1900; Milwaukee had 709, Richmond 615. Then the numbers began to collapse, quickly in the cities, much more slowly on the farms. As the millions of acres that once produced horse feed began producing surpluses, effects of the resulting depressed prices rippled through the economy. In 1933, the Census Bureau suggested the transition to automotive power as a main cause of the Great Depression.

Greene maintains that the abandonment of horses wasn’t inevitable. Objections to the ubiquitous manure, the greater privacy and indepen­dence provided by the automobile, humane considerations—these all played a part, but “the overriding objection [to horses] came from the discomfort of the visible, physical work of power production.” If the explanation for this most fundamental revolution in daily life can be reduced to so few words, then let me reduce it to fewer: man’s fatal attraction to the ­Machine.

Greene’s account is as much about the ­19th-­century cultural landscape as about horses. “Progress,” “civilization,” “prosperity,” become almost a chant, first linked to horses, then turning against them. Especially revealing is her discussion of animal breeding. Americans, in their ebullient new faith in controlling nature, were intent upon molding new horses for new purposes, but myth and prejudice pervaded all. Mules, for example, a hybrid between horses and donkeys that “straddled the border between what in the popular mind were two separate species,” were often discussed in “explicitly racial” terms. Americans “transformed horses,” Greene states, hinting at radical genetic engineering, but ultimately all we know is that a few new specialized breeds emerged, and that horses got much bigger, the result of European ­imports.

As a lifelong horseman and teamster myself, I cannot but wish that Greene had avoided the technics, where she illuminates little, but this is a very small part of a vast scholarly work. As a historian, Greene has limited herself to the descriptive, but in her epilogue, falling out ­of—­or perhaps ­into—­character, she hesitantly suggests a future ­mixed-­energy scene that might include horses. Why so ­timid?