John B. O'Brien
A former juvenile with the touring Augustus Thomas Company, American actor/director John B. O'Brien (aka Jack O'Brien) was Broncho Billy Anderson's cameraman before writing and directing the five-reel The Life of Buffalo Bill (date undetermined), starring legendary showman William F. Cody. O'Brien was reportedly one of D.W. Griffith's assistants on The Birth of a Nation and later directed Mary Pickford in several of her less prestigious vehicles. In the 1920s, O'Brien was demoted to helming low-budget Western two-reelers starring Josie Sedgwick and playing supporting roles opposite the likes of Buffalo Bill Jr. (no relation to William Cody) and Buddy Roosevelt.
~ Hans J. Wollstein, All Movie Guide