One of Levi's customers was Jacob Davis, a tailor who frequently purchased bolts of cloth from Levi Strauss & Co.'s wholesale house. After one of Jacob's costumers kept purchasing cloth to reinforce torn pants, he had an idea to use copper rivets to reinforce the points of strain, such as on the pocket corners and at the base of the button fly. Jacobs did not have the required money to purchase a patent, so he wrote to Levi suggesting that they both go into business together. After Levi accepted Jacobs' offer, on May 20, 1873, the two men received patent #139,121 from the United States Patent and Trademark Office. The "patented rivet" would later be incorporated into the company's jean design (and into later advertising lore). Contrary to an advertising campaign suggesting that Levi Strauss sold his first jeans to gold miners during the California Gold Rush (which peaked in 1849), manufacture of denim overall only began in the 1870s. Modern jeans began to appear in the 1920s.
