At USM, Special Collections' Item of the Month is the "National" Style Book, specifically an issue from 1911. This catalog began in 1872 as a way for people in rural areas to have access to the same types of clothes that inner-city people had. One could order specifically measured pieces, but also whole garments made to a somewhat-standardized size.
Eventually the catalog started being shipped to farther and farther areas, eventually earning the title "National." The catalog is, to the best of knowledge, the first clothing catalog shipped out and able to provide clothing for sale through the mail. Clearly this idea was a very novel idea at the time, but it set into motion the thriving mail-order clothing trend still active today.