The Central Files series documents all major NAM initiatives until about 1970. Prior to its move to Washington, DC in 1974, NAM maintained files in a central location. The subseries and file order reflect how NAM maintained the files. It is arranged into fifty subseries according to subject headings created by NAM. The subject headings are denoted by a subject code, 100-A through 100-ZZ and 200-A. Subject code 100-E, files related to Industrial Relations, were removed from the original run of files and can be found in Series XXV, Open Shop Department and Series XVII, Industrial Relations Department.

The subseries are: General files; Memoranda; Advertising; Promotion; Awards; Industrial Environment Division; Biographies; Inter-office bulletins; Business, Industry, Education Day (BIE Day); Chamber of Commerce; International Labor Organization (ILO); Charters; Government Relations Division — Government finance; NAM policy committees; Conventions; Corporate records; Financial records; Education Department; Free enterprise; Films; International Conference of Manufacturers; Science and Technology Department; Council for Latin America; Inflation; Insurance; International Affairs Division; La Follette Committee; Lobbying; Program Planning Division; Conferences, meetings — other than NAM; Membership; Toland, Lt. Ben; Reports; Organizations, foundations, and associations; Personnel; Positions; Public information — public relations; Publications; Radio and TV; Releases; Religion (clergy-industry); Research; Speeches; Taxes; United Nations; United States government; Women’s clubs; National Industrial Council (NIC); Market Development/Distribution Department; and Urban affairs.

This series should be used in conjunction with individual departments series.

The Chamber of Commerce of the United States is the world’s largest business organization representing the interests of more than 3 million businesses of all sizes, sectors, and regions. This collection contains photographs, negatives, slides, digital images, sound recordings, videos, and films that document the history of the Chamber from its founding to the twenty-first century. The materials provide a record not only of the activities of the Chamber but also of the political landscape surrounding key issues related to business. The collection focuses on the legislation, regulations, and litigation impacting the economy, immigration reform, pensions, health care, trade, Social Security, air quality, global warming, workplace safety, and taxes, as well as major industries such as energy, aviation, automobiles, agriculture, transportation,mining, shipping, and technology.

The Chamber of Commerce of the United States has matured into the largest lobbying group in Washington. Formed in April of 1912 at the request of President William Howard Taft (1857-1930), the Chamber's commitment to be the voice of business is well documented. The records contain articles of incorporation, bylaws, resolutions and minutes of annual meetings. Presentations to Congress, speeches by members, and conferences hosted by the Chamber. Numerous publications give insight into the concerns facing American businesses in the twentieth and twenty-first centuries.