McCord shot over 20 of Maynard's vehicles until 1934, bringing clean compositions and brisk camerawork to a highly enjoyable series of low-budget Westerns. As the 30s wore on, McCord began to work with other stars and studios as well, as on the modest but fun adventure "Carnival Boat" (1932) with William Boyd and Ginger Rogers. By 1936, though, he had settled at Warner Brothers, where, apart from a few years, he would spend the next two decades. McCord continued lensing inexpensive "B" films until the WWII years. While he continued shooting Westerns like "Prairie Thunder" (1937), he had proven himself in other genres by this point. Thus his reliable flair for hard-hitting visuals enhanced such punchy actioners as "Secret Service of the Air" (1938), the especially fine "Bullets for O'Hara" (1941), and even the atypical "Father Is a Prince" (1940).
McCord finally moved up to "A" budget films with the bracing "Action in the North Atlantic" (1943), starring Humphrey Bogart, but his career was interrupted for WWII service. Working for the military's photographic division, McCord rose to the rank of captain, and was one of the first Americans to enter Berlin, photographing scenes in Hitler's chancellery.
McCord's best known and most prestigious films awaited him after his war service, and he stayed with Warner Bros. to bring flair to a wide variety of films. Touching, powerful melodramas like "Deep Valley" (1947), "Johnny Belinda" (1948, which won him the first of three Oscar nominations), and "East of Eden" (1955) used his skill with the outdoors well, and his economical visual narration enhanced more claustrophobic or set-bound films like "The Breaking Point" (1950) and "The Spirit of St. Louis" (1957). Westerns, from "Cattle Town" (1952) to "The Hanging Tree" (1959), never left McCord's repertory, though, and he continued breaking in new directors and making old ones look good into the 60s. His penultimate credit helped end his distinguished career on a high note, when his breathtaking mountain vistas were one of the greatest assets of the sugary family favorite, "The Sound of Music" (1965).