Nugent worked exclusively as a script doctor during his four years under contract to Zanuck and wrote articles on Hollywood for a variety of magazines, including Good Housekeeping, Collier's and The Saturday Evening Post, before writing his first screenplay for John Ford. Ford found Nugent much to his liking, and he ostensibly replaced writer Dudley Nichols as Ford's most frequent collaborator; the two teamed on a dozen pictures during their 15-year association. Though their first two movies together, "Fort Apache" (1948) and "She Wore a Yellow Ribbon" (1949), were not well received at the time, recent criticism has proved less short-sighted, recognizing in these polished works (particularly "Fort Apache") the developing tensions of Ford's Western vision that would culminate in their masterpiece "The Searchers" (1956).
In "The Searchers", Ford and Nugent created a Western hero trapped forever in a world of his own making. He has made civilization possible, but, with the door closing on the wilderness, is forever estranged from the new world. It is this sustained reflection upon the major themes of the Western genre that raised "The Searchers" beyond Ford's other work to the status of tragedy. Regrettably, the two did not follow it with work of similar stature. Their subsequent movies, "The Last Hurrah" (1958), "They Rode Together" (1959) and "Donovan's Reef" (1961) are generally agreed to be of uneven quality as well as variable subject matter.
Nugent occasionally ventured out from under Ford's wing to work with such greats as Robert Wise ("Two Flags West" 1950), Otto Preminger ("Angel Face" 1953) and Raoul Walsh ("The Tall Men" 1955) but never stayed long outside his orbit. Forever linked with Ford, his reputation rests on their collaboration. He won a Writers Guild of America Award for Best-Written Comedy for the boisterous "The Quiet Man" (1952), which teamed John Wayne and Maureen O'Hara, and later shared the same award with Josh Logan for their adaptation of the stage success "Mister Roberts" (1955). President of the Writers Guild of America West from 1957 to 1958, he served a three-year stint (1956-59) as chairman of the building fund committee that oversaw the construction of the organization's headquarters in Beverly Hills.