 He began in amateur theater and later as an actor with A. M. Palmer's organization before returning to teaching at the American Academy of Dramatic Arts.By 1882 de Mille was employed at the Madison Square Theatre reviewing and later revising submitted plays, during which he became acquainted with the playwrights Steele MacKaye and David Belasco.On December 10, 1883, de Mille's first original play, "John Delmer's Daughters, or Duty", opened at the Madison Square Theatre and closed a week later.