A promotional tour brought Warrick from her native Kansas, where she had begun acting, to New York. She met "boy wonder" Orson Welles, promptly became involved with his famous Mercury Theater and quickly made her feature debut in the landmark "Citizen Kane" (1941). As newspaper mogul Charles Foster Kane's first wife, her Emily Monroe Norton, a US President's niece, began sweetly but progressed, via the justly famed breakfast table montage, to being cold and harsh, disillusioned by her husband's megalomania and neglect, even to the point of reading a rival newspaper.
Warrick kept busy in film in the 40s and brought a warm, quiet glow to her many supportive helpmates, but the roles themselves were often rather standardized. She was Douglas Fairbanks Jr.'s leading lady in "The Corsican Brothers" (1941), Pat O'Brien's in "The Iron Major" (1943) and Edward G. Robinson's in "Mr. Winkle Goes to War" (1944), but it was suggestive that VARIETY praised her performance as Randolph Scott's nurse in "China Sky" (1945) as superb, but confused her with Ruth Hussey. Similarly, in 1946 VARIETY praised her beauty and talent in "Perilous Holiday" (1946) but called Warrick's role her "first good break" since "Kane". Playing second leads as well, Warrick did well as the wife whose husband a flashily psychotic Anne Baxter tried to steal in "Guest in the House" (1944), and was even better as Dana Andrews' bitchy spouse in a good Joan Crawford vehicle, "Daisy Kenyon" (1947).
By the early 50s, Warrick was appearing in very modest second features such as "Beauty on Parade" (1950) and "Roogie's Bump" (1954). She ventured into TV hosting the 15-minute NBC anthology drama series, "Short, Short Drama" (1952-53) and recreated Joan Bennett's sensible wife and mother role for the CBS sitcom, "Father of the Bride" (1961-62), based on the 1950 hit film. Stage work ranged from Broadway's "Miss Lonelyhearts" (1957) to musicals with Jackie Gleason ("Take Me Along" 1960) and Debbie Reynolds (a revival of "Irene" 1973-74), to a tour in "The King and I" (1960-61) to nightclub work which further spotlighted her singing ability. Her role as Hannah Cord on ABC's "Peyton Place" (1965-67) netted her an Emmy nomination, and she did very occasional feature work ("Ride Beyond Vengeance" 1966, "Deathmask" 1983) as well. But Warrick won by far her greatest fame beginning in 1970 with her quarter-century reign as Phoebe Tyler Wallingford, prototype for the domineering grand dames Joan Collins and Jane Wyman would later bring to primetime, on ABC's daytime soap, "All My Children".