Look up old U.S. telephone numbers by accessing current and non-current telephone directories at the Library of Congress, which houses an extensive collection of white and yellow pages that are available to the public. As of 2015, pre-1976 telephone directories are mostly in paper copies, while those from 1976 to 1995 are all in microfilm. Phone books from 1996 to the present are considered current and are available as paper copies in the library stacks.
Except for the telephone books of the District of Columbia, Chicago and 14 states, which have been microfilmed, all pre-1976 telephone directories are available only as paper copies, though The Library of Congress continues to convert all pre-1976 telephone books into microfilm. These 14 states include Alabama, Alaska, Arizona, Arkansas and California; Colorado, Connecticut, Delaware, Florida and Georgia; and Hawaii, Iowa, Maryland and Pennsylvania.
Readers request the telephone directory by filling out a call slip in the Local History and Genealogy Reading Room. Write "Telephone Directory" as the call number, the town and state as the title and the year required as the volume number. View telephone directories in microfilm by going to the Reading Room at LJ 139B and accessing the self-serve microfilm collection, which also holds microfilmed telephone books from 1976 to 1995.
Current telephone directories include the years from 1996 to the present, and readers can find them on Deck 46 of the Main Reading Room, where they are filed alphabetically by state. This location also houses many current foreign telephone directories, which are arranged alphabetically by country. The area studies reading rooms also contain some current foreign directories.