When’s the last time you wore nylons? As dress codes change, the hot, oppressive garments have largely gone the way of the dodo. But in the 1930s, their ancestors, silk stockings, were all but required. As Lawrence B. Glickman writes, the average American woman bought up to 15 pairs a year—until, that is, women boycotted the fabric behind the essential garment.

Japan had not yet invaded Pearl Harbor, but in 1937 a nationwide movement emerged to boycott goods made in Japan. Sympathy for China had grown throughout the 1930s, Glickman writes, in part because of Pearl S. Buck and her bestselling books, which idealized the Chinese experience. When Japan invaded China in an undeclared conflict that would later be named the Sino-Japanese War, newly sensitized American women responded by turning their backs on silk.

It was “one of the most popular consumer campaigns in American history,” Glickman writes—so popular that it was supported by a broad swath of groups. Buying silk was characterized as tantamount to killing babies—a reference to the Rape of Nanking, a six-week-long massacre in which thousands of children were killed.

But not everyone got behind the boycott. As Glickman illustrates, it created some strange bedfellows. Unions that usually fell on the consumer side of the argument held that the boycott was unethical because it pushed consumers to non-silk alternatives that were made by non-union workers in ethically problematic conditions. Those who did boycott countered stereotypes of consumer advocates as stuffy and puritanical. Fashion became central to the cause—and sex became central to the conversation.

At the time, writes Glickman, the female leg was becoming a major sex symbol, and that new aesthetic gave the boycotters “a new visibility and resonance.” Fashion suddenly meant sexual and moral power instead of a frivolous distraction from current events. Both sides of the debate showed plenty of leg, invoking “sexuality, spectacle, fashion and pleasure as political forces.”

Fashion shows, stocking burning parties, and pinup-style photos all became weapons in the silk wars. Over time, Glickman notes, the boycott became the first consumer movement to become part of popular culture instead of running counter to it.

Silk stockings never fully recovered. In 1941, as the United States prepared for war, the U.S. blocked Japanese imports. Meanwhile, the invention of nylon set the stage for new leg fashions. By 1942, writes Glickman, “the act of donning or rejecting silk stockings became irrelevant.” But the idea that consumption could also mean morality didn’t—and questions about the origins of our clothing have persisted ever since.