 Prior to production, United Artists had made it quite clear to  director John Sturges (qv) that none of the primary roles were to  be filled by the actors who played the same characters in Sturges  previous Wyatt Earp film, _Gunfight at the O.K. Corral (1957)_ (qv).  Wanting to distinguish this film from the previous one, they  demanded different actors be cast in the roles. However, Sturges  believed that the roles of Virgil and Morgan Earp from the previous  film were small enough that the same actors who played them could do  it again without harming the films uniqueness. The studio agreed  and allowed Sturges to cast John Hudson (I) (qv) (Virgil Earp) and  DeForest Kelley (qv) (Morgan Earp). Unfortunately, Hudson had  retired from acting in the early 60s and was unwilling to do the  role. Kelley, on the other hand, was currently working on the TV  series _"Star Trek" (1966)_ (qv) and was unable to break away to  play Morgan Earp. Thus, both Earp brothers were recast.