Researching older companies can often take a lot of creativity. The answers to the initial questions like "Where was the company located and what did the company do?" can be found in directories. Most researchers seeking information about early or obsolete U.S. companies are well served by consulting the older volumes of the directories listed below as well as the titles in the Obsolete Securities section of this guide.
Some directories focus on an industry some on a place, just keep in mind that depending on the time frame these can be limited. Most industries have directories or related material like credit reference titles that can be helpful (see subject heading browses below). To locate directories find the subject heading(s) for the industry and add the subject subdivision DIRECTORIES to your search. Examples titles from the Library of Congress Online Catalog are: Apparel Trades Book and Lyon Red Book, a directory of furniture industry and trade.
Geographic directories can be found by searching the online catalog for the place name and adding the DIRECTORIES subdivision. The Library of Congress also has a large collection of uncataloged directories that are indexed— our Directories By Address: Inventories of Library Collections guide includes index to street address, criss-cross, and telephone exchange directories as well as guidance to finding city directories. In addition, the Library of Congress recently digitized a large collection of United States Telephone Directories.
The U.S. and foreign telephone books that are in the Library's collections can be requested by place name. You might have to consult them when researching private companies as the directories listed below deal with publicly trade companies in most cases. Another source of information for private companies is local newspapers and trade literature. Newspapers would include stories on, or mentions of, the business but there are also advertisements which can also be very informative. Please see historical newspaper sources listed in the Databases section of this guide.
The following materials link to fuller bibliographic information in the Library of Congress Online Catalog. Links to digital content are provided when available.
Annual Guide to Stocks: Directory of Active Stocks. by Dun and Bradstreet Reference Book of American BusinessNational Stock Summary by Poor's daily reports by Poor's Manual of Railroads by Standard & Poor's Register of Corporations, Directors and Executives. by Thomas Register of American Manufacturers by 
U.S. Telephone Directory Collection
Dun & Bradstreet Reference Book CollectionMoody's Manuals, (now published as the Mergent Manuals, following the acquisition of Moody's by Mergent in 1998), are standard reference sources covering the last century. The manuals provide information on company history, mergers and acquisitions, subsidiaries, principle plants and properties, as well as basic financial data. Only the most recent volumes of the Mergent Manuals are kept on reference in the Business Reading Room. Mergent Archives database offers full collection of digitized Manuals going back to 1909. Data from recent volumes are also available through the Mergent Online database. Both of these databases are by Mergent, Inc. and are available by subscription only. Researchers onsite may use them in the Science and Business Reading Room. Onsite researchers may also request non-current print volumes from the Library's stacks or microfiche copies in the Microform & Electronic Resources Center (MERC). The following list includes the titles in the series with links to earlier and later titles with dates of publication.
Bank and Finance Manual by Moody's Manual of Investments and Security Rating Service by Moody's Manual of Investments: American and Foreign by Moody's Industrial Manual. by Moody's Public Utility Manual. by Moody's Transportation Manual. by Moody's International Manual by Moody's OTC industrial manual. by Moody's OTC Unlisted Manual by 
