This series contains a large proportion of correspondence, but also annual reports of the Warm Springs Foundation and the National Foundation for Infantile Paralysis and other reports, applications, research data, reprints of Dr. Irwin's papers, evaluations of such things as Sister Kenny's famous treatment for polio, salary vouchers and other records which document the career of one of the Foundation's chief staff members. Dr. C.E. Irwin was employed by the Foundation perhaps longer than any other individual and for most of that time in a supervisory capacity. The files actually changed character over the years. In the 1930's and early 1940's, the files consisted almost exclusively of correspondence with patient's families and prospective patient's families concerning treatment at Warm Springs Hospital. In the early 1940's, more subject files were created and the wider scope of Dr. Irwin's interests became clear. It is interesting to note in these subject files the recurrence of certain file folder labels. Such subjects as narcotics, injuries, insurance and National Foundation, for example, appear in virtually every sequence. It should be noted, however, that there are correspondence files scattered throughout all of the subject file sequences.