Jeans are pants made from denim or dungaree cloth. They were invented by Jacob Davis and Levi Strauss in 1873 and a worn still but in a different context. Jeans are named after the city of Genoa in Italy, a place where cotton corduroy, called either jean or jeane, was manufactured. Levi Strauss came from Germany to New York in 1851 to join his older brother who had a dry goods store.
Jeans marked culture of the last 140 years probably more than we think. They were first working clothes, then symbols of disobedience only to become fashion items. History of denim and jeans is long and colorful.
More on the history of denim here