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Site 4
(Constructed for use as a United States Post Office)
Dedicated July 4, 1898
Architect:  William Martin Aitken, Supervising Architect of the Treasury Department, Washington D.C.
1937 additions and alterations: Carl Macomber, Saginaw, Michigan with Smith, Hinchman & Grylls, Detroit, Michigan
1978 remodeling: Toshach & Sobczak Associates, Inc.


Castle MuseumConstructed as a post office and dedicated on July 3, 1898, The French Renaissance Revival architecture of the building was an unusual -  if not unique - choice for a post office.  The building’s architect, William Martin Aitken, claimed that his design was inspired by the early French settlement of the Saginaw Valley.





"The post-office [sic] in Saginaw is accordingly French in style, the corner towers being suggestive of the defensive feature of frontier life, while the carving on the pinnacles finials was suggested by the fauna and flora of the neighborhood."
“The Architecture of our Government Buildings” Engineering Magazine
Vol. 12. p. 823.


The building quickly became a cherished local landmark.  As the population of the City of Saginaw grew, the building was enlarged to meet increased demands.  By the mid-1930s the building had become inadequate to serve the community’s needs, and the federal government proposed construction of a new facility on the site. This proposal met with community-wide opposition and plans were developed to enlarge the existing building. The 1937 addition and reconstruction were inspired by the design of 1896. The  Federal Avenue facade was preserved. The extensive additions resulted in the removal of a tower on the South Jefferson Avenue front, new wings on South Jefferson and South Warren and a large mail sorting room on the south side of the building. Almost all interior spaces were reconfigured and the 1898 lobby was replaced by a new public lobby featuring travertine walls and an oak paneled ceiling. 


Thirty years later, a new post office building was constructed on South Washington Avenue, and the South Jefferson Avenue building was renamed the Castle Sub Station.  In 1970 a new federal office building was dedicated and the building was threatened with demolition.  Again, the community advocated for the preservation of the building and it was transferred to the County of Saginaw to become the home of the Castle Museum of Saginaw County History.


More Photographs

View of Castle Museum, c. 1910


View of building during 1937 renovation


View of building c. 1945; postcard


View of lobby c. 1946; postcard




Rollover map of Historic South Jefferson Walking Tour 100 South Jefferson Avenue 403 South Jefferson - Dow House (This is connected to the First Congregational Church) Jeffers Park 403 South Jefferson - First Congregational Church 600 Federal Avenue 500 Federal Avenue - Castle Museum 505 Janes Avenue - Hoyt Library 303 Jefferson Avenue 310 South Jefferson Avenue 321 South Jefferson Avenue 523 Hayden 411 Hayden 505 Millard 503 South Jeffferson 508 South Jefferson 523 South Jefferson 505 Thompson 518 Thompson 604 South Jefferson 614 South Jefferson 615 South Jefferson St. Mary of the Assumption Cathedral South Jefferson and Hoyt - Location of the fire of 1893


William Martin Aiken. Engineering Magazine. Vol 12, October 1896 - March 1897

Saginaw Courier Herald. 20 January 1897

“Model Post Office Has Few Equals in U.S.” Saginaw Daily News. 18 October 1910

Construction documents, United States Post Office, Saginaw, Michigan. Historical Society of Saginaw County

“Offer Alternate Plans.” Saginaw Daily News. 4 February 1935

“Beauty and Beast Waging Battle.” Detroit Free Press. 18 December 1932

“Enlarge Post Office.” Saginaw Daily News. 7 July 1933

Dedication of Renovated Building.  Saginaw Daily News. 18 August 1937

“Postal Service at the ‘Castle’ Ends June 26. The Saginaw News. 18 June 1976