A small-town Iowa newspaper invented a color-coded class system that the entire English-speaking world adopted.
In 1924, the Alden Times, a newspaper in Alden, Iowa, published a sentence that would embed itself in the English language: "If we may call professions and office positions white collar jobs, we may call the trades blue collar jobs."1 The phrase "white collar" had appeared earlier, in a 1910 Nebraska newspaper that praised homesteaders who had the sense to leave "cheap, white-collar" office work.2
The color coding mapped onto actual clothing. Manual laborers wore blue denim and chambray because the dark color concealed dirt, grease, and sweat. Office workers wore white dress shirts because their work did not soil them.
The distinction gained traction after World War II, when returning veterans streamed into both factories and offices.3 The New York Times printed "blue collar" for the first time in 1945. By the 1950s, the terms had become standard shorthand for an entire class structure, dividing workers not by skill, income, or education, but by the color of what they wore.
Levi Strauss had begun manufacturing blue denim in the 1870s, originally for miners and other laborers in the American West.4 The fabric's association with manual work predated the linguistic label by half a century.
Subsequent decades produced an expanding spectrum. Louise Kapp Howe popularized "pink collar" in the late 1970s to describe women concentrated in nursing, secretarial work, and teaching.5 "Gold collar" appeared in the 1980s for specialized professionals. "Green collar" emerged with the environmental movement. "No collar" described technology workers who rejected dress codes entirely.
The original distinction assumed that the type of work a person did could be identified by looking at them. That assumption has eroded in an economy where a plumber may earn more than a paralegal, and neither wears a uniform to their home office.6