US139121A: Levi's Patent for Tiny Metal pieces on your Jeans

On May 20, 1873, Jacob W. Davis received patent US139121 for an “improvement in fastening pocket openings.” Davis’s improvement consisted of “the employment of a metal rivet or eyelet at each edge of the pocket opening to prevent the ripping of the seam at those points.” 

Those tiny metal pieces are known as 'Rivets' and are placed on areas of the jeans that are most likely to be pulled apart by strain or movement and help hold the fabric together, thereby making them more durable and last longer.

According to The History of Denim available on Levi Strauss's website, May 20, 1873 marked an historic day: the birth of the blue jean. It was on that day that Levi Strauss and Jacob Davis obtained a U.S. patent on the process of putting rivets in men’s work pants for the very first time.

Moreover, Levi Strauss's website also highlighted about necessity of Riveted jeans: One day the wife of a local laborer asked Jacob to make a pair of pants for her husband that wouldn’t fall apart. Jacob tried to think of a way to strengthen his trousers and came up with the idea to put metal rivets at points of strain, like pocket corners and the base of the button fly. These riveted pants were an instant hit. Jacob quickly decided to take out a patent on the process, but needed a business partner to help get the project rolling. He immediately thought of Levi Strauss, from whom he had purchased the cloth to make his riveted pants. Davis wrote to Levi to suggest that the two men hold the patent together. Levi, being an astute businessman, saw the potential for this new product, and agreed to Jacob’s proposal. The two men received patent #139,121 from the U.S. Patent and Trademark Office on May 20, 1873.