The office was, until a few decades ago, the last stronghold of fashion formality. Silicon Valley changed that.

As summer nears, many Americans may be getting ready to change their closets for the new season, making room for the more colorful clothing that goes with the warm weather. Amid all that excitement, it's easy to forget that middle-class Americans have really only been wearing colorful clothes regularly for less than a century.

Athleisure is the future. It seems that every major retailer is trying to jump on the movement that was once thought as just a passing trend, but is now seen as a radical shift in what Americans demand from their clothing. "Athleisure is the new casual," Deirdre Clemente, a professor of history at the University of Nevada, Las Vegas, recently told Business Insider.

Want to channel your inner Jay Gatsby or Daisy Buchanan without looking like a movie extra? We reached out to several stylists, including those involved with the film, to learn how to get this timeless look.

It's not just you — athleisure is everywhere.

Corinne Entratter Sidney, 79, has always loved fashion. She’s been a model and actress, and spent three months as a Copa Girl in Las Vegas in the ’60s, before marrying casino manager Jack Entratter.

Robin Mack Davis is convinced that no one looks in a mirror before they leave home anymore. From the view of her South Elm Street shop, Mack and Mack Clothing, she sees knits and jeans everywhere.

When it comes to the history of women's fashion, taking the gloves off to fight can be taken in a very literal sense.