Today we think of the teenage and youth cultures as one and the same, and it seems to occupy every marketer's thoughts. Youth culture is really American culture, so dominant have the tastes and values of teenagers become.

Even years after leaving their teens, Americans retain not the product preferences from those years but many of the values. We in our great affluence have chosen the greatest of luxuries, never growing old.

Intuitively, though, we know it wasn’t always this way. The popular perception is that the notion of a teenager was born in the U.S. in the mid-1950s with the birth of rock and roll, when drive-ins and sock hops reigned.

But in fact, the rise of the teenager as a force in popular cultural began many decades before, with roots in the latter part of the 19th century.

The notion of the modern American teenager was fully developed by 1945, just as World War II was drawing to a close, following 75 years of evolution shaped by industrialization, urbanization and two world wars. Just a year earlier, in 1944, the word teenager came into being.

“For the last 60 years, this post-war teen image has dominated the way that the West sees the young, and has been successfully exported around the world,” writes Jon Savage in a new book,  “Teenage: The Creation of Youth 1875 – 1945.”

And the caldron for the rise of the teenager was the schoolhouse, the American high school, which was seen as not just a place for education but ironically as an institution to combat the very rebelliousness that came to symbolize teen culture.

As Savage notes, for most of history, certainly up the to latter part of the 19th century, there was childhood and adulthood, with nothing in the middle. And childhood itself was brief. Children were put to work as soon as able. Life was work.

The forces at work in creating the teenage culture were complicated and diverse, but leading them was urbanization, which brought families from farms into cities, and industrialization, which brought young people together in the workforce and put pennies in their pockets.

With both came a phenomenon not seen before, juvenile delinquency, kids with pennies and their pockets and time on their hands wandering about in cities with little to keep them out of mischief.

It was that phenomenon, with the attendant hand-ringing on the part of adults, that first began to define the teenage years as a separate stage of life. That was at the turn of the 20th century.

All wars breed social change, and the first World War served to advance the youth culture, notes Savage, by further undermining the idea of automatic obedience to one's elders. The young men who returned from combat felt their service earned some privileges in return.

The 1920s brought a whole slew of young movie stars, such as Rudolph Valentino, who initiated styles that the young quickly copied, setting them further apart from their parents.

In some ways the Depression, with its widespread poverty, halted the process. Teens were too poor to have lives apart from their parents.

Yet in another way it had a huge impact, and that came through the increased attendance of high school. With so few jobs, it made sense for kids to go to or stay in school longer. But school was also seen as a place to combat juvenile delinquency, a continuing problem.

The surge in school attendance advanced peer culture, setting the stage for the coming eras of swing music and later rock 'n' roll. They were forms of music but they were much more.

“Swing starts to represent the idea of a consumer youth culture in America and internationally,” Savage tells Media Life. “With Swing, you have music, fashions and a whole lifestyle.” 

A defining moment came in the forties during World War II with the launch of  Seventeen magazine, the first truly teen title, one with the aim to further define the teen years as a distinct experience, observes Savage. “The editor went out very aggressively to show marketers, producers and the American media in general that there was a huge untapped teenage market,” says Savage.

By war's end, the teenager was born – and the teenage consumer. Life has not been the same since. Says Savage: “The teenage market has swept everything before it. It is the spearhead of western values throughout the world, for good or ill. It is a huge, huge industry that involves everybody.”

Meanwhile, elsewhere in popcult, “Spider-Man 3” brought in $148 million in ticket sales over its first weekend, breaking the opening weekend record set last year by the second “Pirates of the Caribbean” film.

In DVD rentals for the week ended April 29, according to IMDb.com, three new releases topped the chart, with “Night at the Museum” at No. 1, followed by “Déjà Vu” and “The Queen.”

On iTunes for the week ended yesterday, Maroon 5’s “Makes Me Wonder” was No. 1 for the second straight week, with Carrie Underwood’s “I’ll Stand by You” once again at No. 2.

In books, “The Children of Hurin” by J.R.R. Tolkien fell to No. 2 on the New York Times’ hardcover fiction bestsellers list for the week ended April 28 and to No. 3 on USA Today’s chart for the week ended April 29, replaced on both by the new release “Simple Genius” by David Baldacci.

Walter Isaacson’s “Einstein” remained No. 1 on the Times’ hardcover nonfiction list for a third straight week, though it fell to No. 9 on USA Today’s chart.