It was invented by a Bavarian immigrant, Levi Strauss, who arrived in San Francisco in 1850 at the height of the California gold rush. He noticed that the gold miners needed strong trousers and began making them, first from tent canvas and later from denim with copper rivets to reinforce the seams. The hardwearing garment soon became standard clothing among cowboys and the company has since become one of the worlds largest clothing manufacturers.
Your vote on this answer has already been received
Manish is partly right, Levi Strauss himself was owner of garment factory but failed in his attempt of introducing and selling well know JEANS of today, lost everything and had to work for his livelihood, himself observed that the clothes he wore last for a long period, so he made several such and gave it to the mine workers (since they could not offer). Rest of the things are ok