District of Columbia Biography
Two of the better biographical encyclopedias and social registers to consult for the District of Columbia are:
American Biographical Directories, District of Columbia . . . , 1908-1909. Washington, D.C.: Potomac Press, 1908. (FHL film 1000157.)
Williamson, Stanley. Who's Who in the Nation's Capital. Washington, D.C.: Ransdell, Incorporated, biennial. (FHL book 975.3/W1 D3w 1926/27 and 1929/30.)
Lists of federal employees were published annually in The Official Register of the United States: Containing a List of Officers and Employees in the Civil, Military, and Naval Service. Registers for the years 1863, 1883, 1895, 1909, 1911, 1913, and 1932 are also in book form (FHL book 973 N24o; beginning on film 496565 item 2).
You can find additional information about records for government employees in:
Guide to Genealogical Research in the National Archives. 1982. Revised. Washington, D.C.: National Archives Trust Fund Board, 1985. (FHL book 973 A3usn 1985; 1983 ed. fiche 6051414.) This provides detailed information on the content and availability of census, immigration, military, land, and other records at the National Archives and its branches.
The Family History Library has 1865, 1904, 1907 to 1950, and 1965 editions of the U.S. Congress, Official Congressional Directory for the Use of the U.S. Congress (Washington, DC: Government Printing Office, 1809–; FHL book 973 E4uc; FHL films 1425531-43). Another source you may use is U.S. Congress, Biographical Directory of the American Congress, 1774-1971 (Washington, D.C.: Government Printing Office, 1971; FHL book 973 D3u; the 1903 edition is on film 496555 item 1).