1873: Blue jeans assume their distinctive form when a patent is issued for the rivet process used to strengthen the pockets on what were then called "waist overalls."

Jacob Youphes, a Latvian immigrant who changed his name to Jacob Davis (.pdf) after coming to the United States in 1854, was working as a tailor in Reno, Nevada, when he hit on the idea of using copper rivets to reinforce denim working pants (.pdf). Since he obtained his denim from Levi Strauss & Co. in San Francisco, Davis approached Strauss with an offer to file for a joint patent.

Strauss – knowing a good thing when he saw it – accepted, and the modern "blue jean" was born.

Levi Strauss (.pdf) – himself an immigrant from Bavaria – arrived in San Francisco 20 years earlier, at the height of the California gold rush, to establish a wholesale dry-goods business. From various locations along the San Francisco waterfront, Strauss sold clothing, fabrics and other sundries all over the West, including to miners headed for the gold fields.

The business flourished, but the real turning point in company fortunes came when Davis, a regular customer, approached Strauss with his proposal to form a partnership selling these button-fly, riveted pants, which commanded the then-princely sum of $3 a pair (about 50 bucks in today's moolah). Davis' decision to approach Strauss was a case of simple economics: He didn't have the money to apply for a patent.

Nevertheless, it was the beginning of a beautiful friendship. Blue jeans (a misnomer, since the pants were made of denim and not the lighter cotton textile known as jean) were an immediate success. So impressed was Strauss that he brought Davis to San Francisco to establish and supervise a factory when the demand for blue jeans outstripped the ability of individual seamstresses to make them.

Davis remained at his post until his death in 1908, having sold his interest in the patent to Levi Strauss & Co. the year before he died.

Source: Levi Strauss & Co.