Levi Strauss & Co.
Levi Strauss & Co. created their first pair of Levis 501 Jeans in the 1890s.
We don’t know…
According to the official website: ‘We don’t know why this number was chosen. We also made a 201 jean, which was a less expensive version of the pants, as well as other products using other three-digit numbers. Because of the loss of our records in 1906, the reasons for many of these changes are unknown’.