He was an organizer and the first director (1945–1950) of the Institute of Early American History and Culture, which he moved to Williamsburg, Virginia for five years to oversee.
He argues they grew from small villages to take major leadership roles in promoting trade, land speculation, immigration, and prosperity, and in disseminating the ideas of the Enlightenment, and new methods in medicine and technology.
Contrasted to Europe, printers (especially as newspaper editors) had a much larger role in shaping public opinion, and lawyers moved easily back and forth between politics and their profession.
Bridenbaugh argues that by the mid-18th century, the middle-class businessmen, professionals, and skilled artisans dominated the cities.
He characterizes them as "sensible, shrewd, frugal, ostentatiously moral, generally honest," public spirited, and upwardly mobile, and argues their economic strivings led to "democratic yearnings" for political power.