Worn in the U.S.A.: Denim Turns 138!

Not that you needed an excuse, but instead of donning the old suit and tie to work today, you may want to slip into your favorite pair of blue jeans instead in honor of the timeless apparel's 138th birthday.

On May 20, 1873, Levi Strauss and Nevada tailor Jacob Davis were granted U.S. Patent Number 139,121 for their innovative idea to use rivets to strengthen denim work pants. That unassuming request kick-started a fashion phenomenon that is as quintessentially as all-American as Bruce Springsteen and apple pie and is expected to bring in $54 billion in retail this year, according to a report by the ATA Journal for Asia on Textiles and Apparel.

Here are a few more fascinating factoids about everyone's favorite fashion staple culled from Cotton Incorporated's recent Lifestyle Monitor survey:

Americans own an average of seven pairs of denim jeans.

The term "jeans" has its origins in the French phrase "bleu de Genes," which means "blue of Genoa" and harks back to one of the first known uses of denim pants, as a uniform for Genoese sailors.

When Vogue featured blue jeans on its cover in the early Seventies, denim received its official stamp of approval from the fashion elite.

During WWII, a then-unknown Lauren Bacall modeled denim coveralls on a 1943 cover of Harper's Bazaar in an image that emulated Rosie the Riveter, the iconic character that represented American women who worked in factories while the men were protecting the country.

In 1944, a "scandalous" photo of denim-clad Wellesley College students appeared in Life magazine with a caption that dubbed the style "the sloppy look." The coverage caused a stir and set women's denim-wearing back a good decade.

For more on denim jeans' timeless looks over the years, check out California Apparel News' slideshow of Denim Idols: The Icons Behind the Enduring Style.