The Superintendent of Documents Classification System was developed in GPO’s Public Documents Library between 1895 and 1903. William Leander Post, head of the Library, described it in the preface to the List of Publications of the Agriculture Department 1862-1902 issued by the Superintendent of Documents in 1904. Post credited Adelaide R. Hasse, a librarian working in the library from 1895-1897, for the concept of classification by Government author. Hasse had previously used Government organization authorship to assign classification numbers to the List of Publications of the U.S. Department of Agriculture from 1841 to June 30, 1895, Inclusive while working as assistant librarian in the Los Angeles Public Library. It was published by the Department of Agriculture in 1896 as its Library Bulletin No. 9.
Hasse and Post determined that the best descriptor for Government publications was their origin or authorship, generally expressed not as a personal author but as an agency, bureau, or office. In the scheme, each department or agency in the executive, judicial, and legislative branches, and each independent agency, is assigned an alphabetic symbol, generally although not strictly, mnemonic; thus, A is used for Agriculture Department, C for Commerce, S for State Department, and so on. Two-letter and three-letter symbols have been used as necessary: FS for Federal Security Agency (in the 1930s); HE for Health, Education, and Welfare, later transferred to Health and Human Services; NAS for NASA; and HS for Homeland Security. Congress, as well as Congressional committees and commissions, are designated X and Y.
Basing the classification on current Federal Government organization can be challenging. New federal agencies are created, older agencies cease operation, bureaus can be newly created or merged, or functions transferred to another agency. When the Department of Homeland Security was established in 2002, it took bureaus and subordinate offices from Treasury, Defense, Justice, and several others, as well as incorporating the formerly independent agency, the Federal Emergency Management Administration (FEMA).
The Superintendent of Documents classification system continues to classify by Government author. It has been used for over 100 years to identify Government documents distributed to depository libraries and described in the Catalog of U.S. Government Publications. The system is also used by the National Archives and many libraries in the Federal Depository Library Program to organize their collections.