Buchanan appeared in more than 100 films, including "Texas" (1941), in which he played a dentist and appeared with William Holden and Glenn Ford and later in "Penny Serenade" (1941) with Irene Dunne and Cary Grant, "Tombstone, the Town Too Tough to Die" (1942), "The Talk of the Town" (1942) with Ronald Colman and Jean Arthur, "The Man from Colorado" (1948), "Cheaper by the Dozen" (1950), "She Couldn't Say No" (1954), "Ride the High Country" (1962) with Randolph Scott and Joel McCrea, "McLintock!" (1963) with John Wayne, "Move Over, Darling" (1963) with Doris Day and James Garner, and "Benji" (1974).