When Levi Strauss & Co. covered the back pocket rivets in 1937, everyone thought that would solve the problem of rivets scratching their furniture when they sat down. But those copper rivets were tougher than they looked—after a few years of hard wear, they continued to break right through the denim, scratching things up again. By 1966, technology had caught up with history, and it was possible to bar tack the 501® Jean’s back pockets, replacing the back pocket rivets. The text on the pocket flasher indicates this change. This small change maintained the jean’s notorious durability, while finally solving that decades-long furniture-scratching issue. This particular style of 501® Jean—with bar tacks and a big “E” red Tab— only existed from 1966 to 1971. What does this mean for the 1966 501® Jean? It means someone who hitchhiked their way to San Francisco in 1967 and bought a pair of 501® Jeans was not only experiencing a once-in-a-lifetime event, but was wearing a unique pair of jeans—a pair which would change again when the Summer of Love was just a faded memory.