S.L.A. Marshall reportedly disliked the fact that he had sold the movie rights to his book for next-to-nothing, and vowed not to make the same mistake again. In January 1958 Lewis Miilesone agreed to direct. He and Bartlett wanted to cast unknowns in support of Peck and saw over 600 actors for 83 speaking parts. Strode and Edwards' portrayal of African American soldiers is based on the 24th Infantry Regiment, which was still racially segregated in Korea. All Black units were integrated in the summer and fall of 1951 and all Black units were integrated and closed out on 1 October 1951. Like its cinematic portrayal, the real regiment was poorly trained, poorly equipped and poorly led. More than once when this all-black unit was placed on the front lines, a unit in reserve was positioned directly behind because they were expected to break. The regiment was finally considered so unreliable it was disbanded. Its personnel were reassigned to other combat units just as in the film, which portrays Edwards' character - with good leadership - becoming an effective soldier. George Shibata, who stars as Lt. Suki Ohashi, became the first Nisei appointed to West Point through the sponsorship of Sen. Elbert D. Thomas. Shibata would become the first Asian American graduate of the United States Military Academy, Class of 1951 and he was commissioned in the United States Air Force later in that same year (1951). During the Korean War he flew an F-86 Sabre out of Taegu Air Force Base. The film Pork Chop Hill was about Shibata's classmate Joseph G. Clemons, who was also a 1951 West Point graduate. This came about when Clemons accidentally bumped into his old friend Shibata at a drugstore when Clemons was in California acting as a technical adviser for the forthcoming film. He convinced Shibata to try out for the role of the Hawaii born Japanese-American Executive Officer, Lt. Tsugio Ohashi when Hollywood was having a problem casting the role. During the production Clemons decided to play a joke on his Air Force pilot classmate whose accommodations during the war were more comfortable than Clemons' by ensuring that Shibata wore the only actual flak jacket in the film; the other cast members wearing foam rubber reproductions. Filming started 19 May 1958. Some of the location shooting was conducted in California near Westlake Village and in San Fernando Valley. Two months before filming the unit moved into an Albertson Company Ranch where the bulk of the film was to be shot and created a series of trenches.