An Engineer’s Guide to Baltimore, http://www.ce.jhu.edu/baltimorestructures/Home.php
Bancroft, Hubert Howe. The Book of the Fair: Chicago: Bancroft, 1893.
The Baltimore Alliance for Great Urban Parks: “Discovering Baltimore’s Parks: The Legacy and an Overview,” January 2002 (revised August 2004, March 2007)
Baltimore Architecture Foundation (with special thanks to James T. Wollon, Jr., A.I.A., Architect Emeritus, for much information, time, insight and good humor)
The Baltimore Architecture Project: Baltimore Buildings http://www.baltimorebuildings.org/
Baltimore Ghosts website
The Baltimore Sun: 16 June 1880; 14 March 1920; 22 September 1954.
Chalkley, Tom. "Built to Last." "Charmed Life". City Paper, Baltimore, 10 November 1999.
Dorsey, John and James D. Dilts. A Guide to Baltimore Architects. 3rd Edition. Centreville, MD: Tidewater Publishers, 1997.
Ellis, Jeff with City of Baltimore for his knowledge and photos of Druid Hill Park
Enoch Pratt Free Library: "The Cator Prints: City Hall, Now & Then."
Forrester, Allen E. (Compilator):The City Hall, Baltimore: history of construction and dedication, 1877.
Frederick, George A. "Recollections of George A. Frederick" 1912. Maryland Historical Society
"Frederick, George Aloysius." The National Cyclopaedia of American Biography being the History of the United States. Vol. IX. New York: James T. White & Company, 1899. p. 334.
Giza, Joanne and Catharine F. Black. "Cylburn." Great Baltimore Houses: An Architectural and Social History. Baltimore: Maclay & Associates, 1982. p. 79-81.
Hayward, Mary Ellen and Frank R. Shivers, Jr. The Architecture of Baltimore: An Illustrated History. Baltimore: The Johns Hopkins University Press, 2004.
Howard, George Washington: The Monumental City: Its Past History and Present Resources, 1873
Jones, Carleton. Lost Baltimore Landmarks: A Portfolio of Vanished Buildings. Baltimore, MD: Maclay & Associates, Inc., 1982.
Journal of the American Institute of Architects, November, 1924
Maryland Journal, 29 September 1883
Mother of Churches: A History of St. Mary's Church, Hagerstown, Maryland. 1976
Open Green Map
Pennsylvania Bureau for Historic Preservation, Pennsylvania Historical and Museum Commission, State Historic Preservation Office
Perlman, Bennard B. “The City Hall, Baltimore” Maryland Historical Magazine. Maryland Historical Society. Vol. XLVII. no. 1. March 1952. p. 40-54.
"Poe's Grave" The Edgar Allan Poe Society of Baltimore. 2 January 2001.
Primm, Chauncy, for his photos
Sears, Russ for his historical artifacts
Schaumburg, Wayne, for his knowledge and pointing me in the right direction
Smith (Dixon), Kathryn. A Baltimore Architect Remembers: Commentary on the “Recollections of George A. Frederick,” 2002
Thomas, John: The Chronicles of Baltimore (1874)
Unger Bowditch, Eden and Draddy, Anne: Druid Hill Park: The Heart of Historic Baltimore, 2008
Van Arsdale & Co.: The stranger’s guide to the city of Baltimore, (1875)
Weeks, Christopher: An Architectural History of Harford County, Maryland. 1996
Withey, Henry F. and Elsie Rathburn Withey. Biographical Dictionary of American Architects (Deceased). Los Angeles: Hennessey & Ingalls, Inc., 1970. p. 220-221.
And of course, all the other amateur historians who have helped in this endeavor.