In European and early American white society, people were most interested in being as pale as possible.This meant you were rich because you did not have to work in the sun. It was a pretty effective class stratification, because anyone of the lower classes had to work in the fields, and they got very dark. At the time the classes were very divided on genetic lines, and what you were allowed to be, depended entirely on your family history. This continued to be the standard until the industrial revolution, when the lower classes were crowded into factories and became as pale as lords and ladies. I'm not sure what they did in England, they may have solidified their upper-crust accents. But in America, the experiment was to be egalitarian, and so your class was more decided by your wealth, not your blood line. The tilt towards tans happened sometime after the 1920's. Suddenly young women had the vote, were going to real colleges, the stock market was booming, everyone was traveling. Very Gatsby. Among the upper classes, everyone had a car, people had leisure time, they traveled the world, creating the jet set. A tan was proof that you could have a vacation. If you were a hick you tanned in the shape of your overalls, but if you were a rich person who sat in the sun and had vacations, you had no tan lines. After color film was invented, all the movie stars became sun worshippers, portraying attractive people living adventurous lives. Contrast the leathery face of an old Gary Cooper to his pale face in the silent era.