An obituary in the New York Times observed that from the 23 books that he wrote between 1950 and 1973, Plumb became wealthy enough to "indulge his taste for fine food and wine;" to build a collection of rare porcelain; to drive a Rolls-Royce; and to live in a "16th-century rectory in Suffolk, a mill in the south of France and a Manhattan pied-à-terre in the Carlyle Hotel.
"[1] Plumb is seen as mentor to a school of historians, having in common a wish to write accessible, broad-based work for the public: a generation of scholars that includes Roy Porter, Simon Schama, Linda Colley, David Cannadine and others who came to prominence in the 1990s.
He was champion of a 'social history' in a wide sense; he backed this up with a connoisseur's knowledge of some fields of the fine arts, such as Flemish painting and porcelain.
This approach rubbed off on those he influenced, while he clashed unrepentantly with other historians (notably Cambridge colleague Geoffrey Elton) with a perspective from constitutional history whose emphasis was on more traditional scholarship.
Friends from his early life, C. P. Snow and William Cooper, portrayed him in novels; he also is known to be the model for a character in an Angus Wilson short story The Wrong Set.