Whatever happened to horses? They were once an integral part of daily life. Visitors to Tudor and Stuart England called it the kingdom of the horse because of the preeminence of the horse in the “economy, social and political life, in learned and agronomic discussions and as an object of both aesthetic and utilitarian concern” writes historian Daniel Roche.

Roche writes that this now-vanished world of daily equestrian culture was utilitarian, exploitative, and also something more. “As it involved living beings, it stimulated sensibilities, establishing constant links between thought and action, horse and horseman, horses and those who domesticated them, mobilized them, loved them or rejected them.”

Indeed, horses were once so ubiquitous that they gave their name to a measure of power: horsepower, essentially the power that one horse produces. The term was coined and calculated by James Watt in the 1770s. The measure was initially a marketing tool; he wanted to compare his steam engine to the number of draft horses it would replace.

It took a while, however, to replace the power of horses with mechanical horsepower. In the early twentieth century, forty-horse teams pulled individual combines in the wheat fields of Washington. There were issues, of course, with using horses for so much. In 1872, Boston’s business district burned down when the fire department’s steam pumping engines couldn’t get to the fire… because the horses that pulled the engines were down with the flu. In 1880, 15,000 dead horses were removed from New York City’s streets, to be converted into leather hides, dog meat, glue, fertilizer, furniture stuffing, candles, and soap. The waste from the city’s 200,000 living horses presented another disposal problem: an individual horse produces 15-30 pounds of manure and a quart of urine per day.

In the nineteenth century, horses were “living machines,” says historian Clay McShane, who details the increasing growth of horse use during Boston’s “Gelded Age.” Horses were used for “freight delivery, passenger transport, food distribution, and police, fire and ambulance services.” Caring for and cleaning up after horses (or not: cities were a pestilence of horse flies) were industries unto themselves. As late as 1900, more than 11,000 Bostonians earned their living driving horses.

McShane writes that, viewed from an ecological perspective, the horse/human connection was symbiotic, two mammals sharing habitat. Yet he also notes that it was an abolitionist who founded the Massachusetts Society for the Prevention of Cruelty to Animals in 1868: the terrible cruelty humans could inflict on other humans in slavery was unfettered when it came to abuse of work animals.

As recently as a century ago, horses were still everywhere, omnipresent in rural and urban areas alike. Even during WWII, write historians R. L. DiNardo and Austin Bay, horses played an enormous role in transport and European agriculture, which suffered tremendously because of their appropriation for war. The Germans—supposedly the most mechanized military of the day—were highly dependent on horse-drawn transport. The Russian horse population has been estimated at 21 million before the war, 7.8 million after.

Since then, of course, things have changed, and “horse-power” exists only as a metaphor used to sell cars. Humans worry about replacement by machines, but horses have already experienced this and for them it may well have been a good thing.