Jeans was a blue twilled cotton cloth milled in Geneo, Italy. The French weavers called the town "Genes" - and that's how we got the word "jeans".
Blue jeans were invented by Levi Strauss during the Gold Rush of the 1850s. Selling canvas to the miners, he started stitching it into pants. In the 1860s, he replaced the canvas with denim. Worn as work pants for years, they became fashionable in 1935 when a model wore then in Vogue magazine.
Taken from Celebrate the Date