In 1873, the United States granted design patent to Levis Strauss, (an immigrant from Bavaria) and thus modern American denim blue jean was born.

During those days it was used mostly by Mine Workers, Iron Smiths and people working in dangerous conditions to protect themselves from scratches and injuries. 

Though it was accidently made in 17th Century, in mid-19th century America, Jean Fabric was used for trousers and overcoats and was solid colored, usually indigo, olive, or brown. Denim, then was always spun from both white and indigo yarn, and was used mostly by workwear for miners, mechanics, cowboys, and farmers that required the toughest materials.