In so many photos industrial workers are pictured wearing suits and flat caps, in the modern day the suit is viewed as a corporate elitist outfit. How did this shift happen?
There is always more to be said, but you may be interested in my previous answer to What factors led to the downturn in menswear hat sales in the 1960s? - despite the hat-specific title, I discuss the decrease in formality/increase in casual dress in the mid-20th century.