The leather jacket has its roots in military and aviation history. During World War I, aviators wore leather jackets to protect themselves from the harsh cold of high altitudes. By the 1920s, these jackets were adapted for everyday use, with styles like the bomber jacket gaining popularity. In the 1950s, the leather jacket became associated with rebellion, particularly through iconic figures like Marlon Brando in The Wild One and James Dean in Rebel Without a Cause.