Series 2: Subject Files, Subseries 3: Department of Labor (1945-1954) consists of material relating to Morse's tenure as Assistant, Under, and Acting Secretary of Labor in the Truman administration between July 1946 and August 1948. For the most part, the contents of this subseries can be divided into three broad categories: intra-departmental material, inter-departmental material, and extra-departmental material. It is important to note that most of this material takes the form of copies of records held in the National Archives rather than papers held in Morse's files. Their character tends to be impersonal, not that the human dimension is entirely absent. Morse's dealings with Secretary Lewis Schwellenbach and the upper echelons of the department convey a clear sense of the style and substance of his administrative role. The topics covered in this subseries are varied, ranging from the contentious Taft-Hartley Act of 1947, to the family budget of urban workers to the equitable participation of minorities in the programs and services of the department.

The bulk of the material in this subseries is intra-departmental, including budget reports, general orders establishing policies and procedures for various activities, draft legislation, statutes describing the purpose of departmental units, and plans for the department's 35th anniversary. This category also contains material relating to programs and services within the jurisdiction of the department such as the United States Employment Service, the Women's Bureau, the Federal Mediation and Conciliation Service, and the Veterans Employment Service. The activities of the department itself are documented in large part through reports on the progress of various domestic and international programs and through memoranda between officials suggesting changes within or alternatives to such programs.

The inter-departmental material in this subseries consists of documents exchanged between the department and other governmental offices and officials, including reports on joint programs and issues of departmental concern. For example, the Department of Labor, the Department of Commerce, and the Department of Agriculture were all involved in the Food Conservation Program established by President Truman. The White House, the Department of Justice, the Federal Bureau of Investigation, and the Atomic Energy Commission were also among the department's correspondents.

For its part, the extra-departmental material consists of correspondence and associated documents exchanged between Morse or his colleagues and external bodies such as the International Labour Organisation, the Merrill-Stevens Dry Dock and Repair Company, United States Steel, and the University of California's Institute of Industrial Relations. A number of congratulatory letters and telegrams from Morse's friends and relations on the occasion of his appointment as Assistant and Under Secretary of Labor inject an element of personal warmth into this subseries.