The superhero of comic books and blockbuster movies may be a quintessentially American invention, forever saving the world in skin-tight spandex. But the cultural DNA of the superhero can arguably be traced to a much older, more progressive, British tradition: the larger-than-life folk heroes of historical protests - General Ludd, Captain Swing, Lady Skimmington, and others; semi-fictional identities that ordinary protestors adopted, often dressing...