Levi Strauss & Co.
San Francisco wholesaler that patented riveted work trousers with Jacob Davis in 1873; the 501 is the classic model.
Levi Strauss came from Bavaria to San Francisco during the Gold Rush and ran a wholesale business in fabrics and clothing. The tailor Jacob Davis hit on reinforcing the pockets with copper rivets, and they received a patent together in 1873.
Lot 501 got its number around 1890, and the red tab on the back pocket came in 1936. Jeans went from workwear to youth fashion in the 1950s, and Levi's still owns a large archive of old garments.
The red tab on the back pocket; before 1971 it read LEVI’S with a capital E, afterwards Levi’s.