The Meaning of 1870: The year everything changed.

• Author: DeLong, J. Bradford

Before 1870, inventions and innovations had by and large been singular discoveries and adaptations. They produced new and better ways of doing old things: of making thread, of weaving cloth, of carrying goods about, of making iron, of raising coal, and of growing wheat and rice and corn. Having pioneered these improvements, their inventors then set about finding ways to exploit them. It was a process that required inventors to be not just researchers but development engineers, maintenance technicians, human resource managers, bosses, cheerleaders, marketers, impresarios, and financiers as well.

That pre-1870 system was good enough as long as the confluence of circumstances was just right. Consider the invention of the steam engine in the eighteenth century. It needed a cheap source of fuel, it needed something important and profitable to do, and it needed societal competence at the metalworking technological frontier. Fuel was found at the bottom of the coal mines. With the steam engine, cheap, plantation-grown cotton, ideally suited for machine spinning, quickly reached factories that produced sought-after goods. And with practical metallurgy to make iron rails and iron wheels cheaply, the fuse that was the Industrial Revolution was lit. Steam power propelled the automatic spindles, looms, metal presses, and railroad locomotives of the nineteenth century.

But the fuse might well have sputtered out. That, after all, is what the pre-1870 track record would lead one to expect. Printing, the windmill, the musket, the seagoing caravel, the water mill, and before that the horse collar, the heavy plow, the 3,600-soldier legion-each of these did revolutionize a piece of the economies and societies of their day. Yet none of them lit anything like the rocket of economic growth we have ridden since 1870. Ancient Mediterranean civilization was followed by what is rightly called a Dark Age. Printing revolutionized the dissemination of information, but books were always a small part of total spending, and the printing press was one revolutionary invention, not a series of them. The windmill and the water mill meant women no longer had to spend so much time nose to grindstone, but their fathers and husbands found other things for them to do instead. The musket and the caravel made the Imperial-Commercial Age and the gunpowder empires, but that, again, was a discrete jump rather than a takeoff into sustained growth. The horse collar and the heavy plow...