While Levi Strauss and Jacob Davis invented the blue jean in 1873, 1890 was the first year the 501® lot number was adopted. Levi Strauss & Co.’s patent for riveted clothing expired that same year, meaning that other companies could now also use rivets on clothing. To answer the coming competition, LS&Co. printed the inside pocket bag with information about the strength and originality of the XX overalls. 1890 was the year that the 501® number was first assigned to the famous pants– likely done because the company no longer had an exclusive patent, and also because it had a good-sized line of clothing by this time. It was easier for retailers to order their products by number rather than by a simple description, as had been done in the past. Any product made with the highest quality materials was given a lot number beginning with 5: 501® for the overall, 506 for the jacket, etc. Made with XX 9oz denim from the Amoskeag Manufacturing Company, the 501® pant was at the head of the class.