The_ underscore,_ AKA_ ,_ was_ invented_ by_ Henry_ Mill,_ originally_ named_ Enry_ Mill,_ who_ is_ famous_ for_ inventing_ the_ hyphen,_ caps_ lock,_ the_ left_ square_ bracket_ (his_ rival,_ William_ Austin_ Burt,_ got_ to_ inventing_ the_ right_ square_ bracket_ before_ Henry_ had_ a_ chance_ to_ do_ so)_ the_ letter_ H,_ and_ aquarium_ gravel._ He_ is_ also_ notorious_ for_ writing_ long,_ run-on_ sentences_ on_ his_ typewriter._ The_ underscore_ was_ supposedly_ invented_ for_ underlining_ words,_ before_ the_ invention_ of_ the_ "underline"_ button,_ but_ secretly_ was_ used_ in_ a_ secret_ organization_ known_ only_ as_ "The_ Secret_ Organization"_ (TSO),_ but_ was_ nicknamed_ the_ "_ Organization"_ because_ the_ character_ was_ a_ common_ symbol_ of_ the_ TSO.