The Maryland Historical Society and the Enoch Pratt Free Library at http://www.prattlibrary.org/ have major collections of biographical materials. The "Biography File" at the Enoch Pratt Free Library is a 180-drawer card index to newspaper clippings, local histories, and periodicals from the 1800s and 1900s.
A valuable guide to biographical sketches is:
Andrusko, Samuel M. Maryland Biographical Sketch Index. Volume 1. Silver Spring, Maryland: Samuel M. Andrusko, 1983. (FHL book 975.2 D3a) This indexes over 10,500 biographical sketches.
Eleanor Passano's book (see the "Genealogy" section of this outline) is an excellent index to biographical and genealogical information. Indexes to the Maryland Historical Magazine give references to numerous biographical sketches. Other excellent card indexes are at the Enoch Pratt Free Library and the Maryland State Archives. Also search statewide, regional, and county histories for biographical information.
The following are examples of helpful collections of biographical information:
Papenfuse, Edward C., et al. A Biographical Dictionary of the Maryland Legislature, 1635-1789, Two Volumes. Baltimore, Maryland: Johns Hopkins University Press, 1979, 1985. (FHL book 975.2 N2p) This dictionary has considerable information on early Maryland families.
Spencer, Richard Henry. Genealogical and Memorial Encyclopedia of the State of Maryland . . . Two Volumes. New York, New York: The American Historical Society, 1919. (FHL book 975.2 D3s; film 1000060; fiche 6046929) This work contains three- to four-page biographical sketches.
Men of Mark in Maryland: Biographies of Leading Men in the State. Four Volumes. Washington, D.C.: Johnson-Wynne Co., 1907-12. (FHL book 975.2 D3m). This work contains three- to four-page biographical sketches.
Biographical Cyclopedia of Representative Men of Maryland and District of Columbia. Baltimore, Maryland: National Biographical Publishing Co., 1879. (FHL book 975 D3b; film 1000059 item 3).
The Locality Search of the Family History Library Catalog lists more of these records under:
MARYLAND - BIOGRAPHY
MARYLAND, [COUNTY] - BIOGRAPHY