Hugh J. Krampe began acting on stage in the late '40s and debuted in films in 1950 with Ida Lupino's drama Never Fear. Soon he was appearing in low-budget actioners, mostly westerns such as Raoul Walsh's The Lawless Breed and Saskatchewan and Budd Boetticher's Seminole and The Man from the Alamo. O'Brian began breaking into bigger-budget films, including Edward Dmytryk's Broken Lance, when he found celebrity starring in the television western series The Life and Legend of Wyatt Earp from 1955-61. O'Brian's other notable oaters include Gordon Douglas' The Fiend that Walked the West and John Wayne's final film, Don Siegel's The Shootist; his other notable films include Kurt Neumann's science-fictioner Rocket Ship X-M, Otto Preminger's war drama In Harm's Way, and Ivan Reitman's comedy Twins.