This series comprises ministerial files and papers maintained by Harold Edward Holt in his first portfolio, as Minister Assisting the Minister for Supply and Development, from April 1930 to March 1940. However, Holt was also Minister in Charge of the Commonwealth Council for Scientific and Industrial Research (CSIR) in this period, and acted as Minister for Civil Aviation in November-December 1939. A small number of items reflect the additional portfolio responsibilities. 

The content of the series includes correspondence, reports and reference material relating to air transport services, aircraft manufacture, clothing for the militia, Economic Committee, Education Council, national development, national fitness, national planning, R G Casey, R G Menzies, skilled artisans, technical training, Supply and Development Bill 1939 and other departmental matters. There is also a file containing congratulatory messages to Holt on his entry into the ministry. Many of the files have Department of Supply and Development file covers. The subject titles are written on the covers but there are no file numbers.

The records were transferred to archival custody in Melbourne by the Department of Supply on 25 September 1959 and initially controlled as MP392, Bundle 1 (ref. RWM 24/1/13). They were relocated to Canberra in December 2001, and the series description revised, as part of the Prime Ministers Papers' Project.