These days, most foods don't go out of their way to advertise their high gluten content. But in many old ads, it was a selling point.
This ad from 1905 for Pillsbury flour is typical — beneath a bizarre reference to Chinese customs, you'll find the boast that "the gluten and phosphates of the best wheat are retained by the Pillsbury Process."
During World War I, Pillsbury bragged about all the "nourishing" gluten in its flour — part of a serious wartime effort to keep kids healthy.
What does the early gluten fever mean? Who knows. Today, you'd never get away with ads like these because of the gluten-free craze (which has its own problems).
This obviously wasn't the case in 1919. "Gluten?" an ad from Merit Bread asks. "That's the something which helps to make you thrive."