In 1872 the U.S. economy was growing as the young nation industrialized and expanded westward. Then in the autumn, a sudden shock paralyzed social and economic life. It was an energy crisis of sorts, but not a shortage of fossil fuels. Rather, the cause was a virus that spread among horses and mules from Canada to Central America.
For centuries horses had provided essential energy to build and operate cities. Now the equine flu made clear just how important that partnership was. When infected horses stopped working, nothing worked without them. The pandemic triggered a social and economic paralysis comparable to what would happen today if gas pumps ran dry or the electric grid went down.
The equine influenza first appeared in late September in horses pastured outside of Toronto. Within days most animals in the city’s crowded stables caught the virus. The U.S. government tried to ban Canadian horses, but acted too late. Within a month border towns were infected, and the “Canadian horse disease” became a North American epidemic.
By December the virus reached the U.S. Gulf Coast, and in early 1873 outbreaks occurred in West Coast cities.The flu’s symptoms were unmistakable. Horses developed a rasping cough and fever; ears drooping, they staggered and sometimes dropped from exhaustion. By one estimate, it killed 2% of an estimated 8 million horses in North America. Many more animals suffered symptoms that took weeks to clear.