Between the two World Wars an extensive body of writings appeared in the United States explicitly or implicitly on the historical development of the sciences. I am not referring to the vast literature of popularization in magazines and newspapers but to substantial works, often in book form, coming from various intellectual and scholarly traditions. Only a few examples are classifiable by later standards as professional history of science. Following Arnold Thackray, one can designate some authors as ‘proto-historians’ of science. Most (...) of the writings, including those of the ‘proto-historians,’ have distinctive attributes: methods, attitudes and goals, reflecting traditions other than professional history of science or even the general history exemplified by the American Historical Association's membership of that era. What follows is a bird's eye view of a past of interest for its own sake and for clues about the professionalization of history of science after 1950. (shrink)