10 North 2nd Street, Harrisburg, PA 17101
(717) 255-3040
How to Research your Historic Home: Sanborn Maps
If you want to research the history of a building, Sanborn maps are a great starting point. The Sanborn Map Company published maps every few years, beginning in the late 19th century, many of which are now in the public domain. These maps documented Harrisburg in 1884, 1890, 1905, and 1929, which provides an interesting glimpse into how the city changed over time and a way to estimate when buildings were constructed.
History
The Sanborn Map Company created fire insurance maps of U.S. municipalities with populations over 2,000 from 1867 through 1977.[i] Because fire insurance companies relied on these maps to assess their total liability, the field surveyors and cartographers included building footprints of main structures and outbuildings, exterior wall and roof materials, roof types, window locations, building use, fire escapes, and the locations of hydrants, sprinklers, gasoline tanks, and water pipes. The level of detail included in Sanborn maps provides a unique glimpse into how municipalities across the country developed over time through the physical changes in neighborhoods and changes in use.
Each Sanborn map includes a cover page, index, and a key. The maps also include the total population count, information on the fire department(s), water facilities, land grading, and prevailing winds.
Please note that some street names change. For instance, Cameron Street was once 11th Street, Green Street was once Two and One Half Street, etc. The page keying each sheet to the larger map is helpful to reference in these cases.
User Guide – Harrisburg, October 1884
Harrisburg’s 1884 Sanborn map covers the smallest area by acreage. The map includes parcels roughly bound between Granite Street to the north, 10th Street to the east, Sycamore Street to the south, and Front Street to the west. A few blocks to the east of 10th Street, usually detailing commercial or industrial sites, are also included, but parcels outside of the immediate surrounding areas to these sites were not recorded.
The 1884 Sanborn map indicates the number of stories, the exterior wall material, roof material, cornice material, if there is a frame partition between dwellings, where the windows are located, and the locations of stables (Figure 1).[ii]
Looking at Sanborn maps can aid in estimating when a building was constructed. For example, 21 North Front Street was built sometime before 1884, since the building is featured on the 1884 Sanborn map (Figure 2).[iii] The building number is below the building footprint; 21 North Front Street is the third building from the right with the light blue color at the front of the structure. The Sanborn map shows the footprint of a three-story brick building with a stone front and wood cornice, which is an accurate description of the existing structure.
User Guide – Harrisburg, August 1890
As Harrisburg’s population grew, subsequent editions of the Sanborn maps covered more land. Harrisburg’s 1890 Sanborn map covers parcels roughly bounded by Maclay Street to the north, 11th Street (now Cameron Street) to the east, Sycamore Street to the south, and Front Street to the west. Similar to the 1884 map, some blocks are not included within the boundaries stated above, and some blocks beyond those boundaries are included. Ten blocks of Allison Hill beyond the eastern boundary are documented, as well as the Harrisburg State Hospital grounds. The 1890 Sanborn map displays the same information as the 1884 map (Figure 1).[iv]
Comparing Sanborn maps provides information about construction dates. The homes at 107-109 Cumberland Street are not seen on the 1884 Sanborn map, but were documented on the 1890 Sanborn map (Figure 3).[v] The maps show that sometime between 1884 and 1890, the two-story brick structures with metal cornices were erected on the same area where two shops once stood. Notably, the original addresses were 109-111 Cumberland Street. Just as street names change, individual home addresses do as well.
User Guide – Harrisburg, November 1905
The November 1905 Sanborn map has similar boundaries to the 1890 iteration. The 1905 Sanborn map includes more blocks within the boundaries. Maclay Street is still the approximate northern boundary, but more parcels are documented leading up to this boundary. More parcels to the west are also included; a larger portion of Allison Hill, Summit Terrace, and Mount Pleasant is documented, as well as a portion of Penbrook.
The key for the 1905 Sanborn map includes more expands upon the prior two map keys (Figure 1).[vi] Additional construction materials, such as fireproof exterior walls and composition roofs, are now included, as well as notations regarding iron doors and window shutters.
Sometimes building footprints look similar, but the changes in construction materials, and possibly the number of stories, aids in identifying the changes to the parcel. In the 1890 and 1905 Sanborn maps, a large rectangular building is documented at 1003 Capital Street (Figure 4). The extant building is a three-story brick building. The 1890 Sanborn map displays a two-story, frame slaughterhouse; the 1905 Sanborn map shows a three-story masonry plumbing and tin shop with a metal cornice, which matches the appearance of the existing building. The existing building also includes text within the cornice identifying it as a plumbing and tinning shop owned by the Fisher brothers, which further confirms this building is the same one documented on the 1905 Sanborn map, and was thus constructed sometime between 1890 and 1905.
User Guide – Harrisburg, October 1929
The October 1929 Sanborn is the latest Sanborn map of Harrisburg to enter the public domain. This map was the first iteration published in two volumes, and documents the majority of the properties within city limits. The first volume is roughly bounded by Boyd Street to the north, South 18th Street to the east, Elliot Street to the south, and Front Street to the west. The second volume is roughly bounded by Estherton Avenue to the north, South 34th Street or Walker Mill Road (now Progress/Paxtang Avenue) to the east, the Philadelphia & Reading Railroad to the south, and South 18th Street to the west.
The 1929 map key significantly expands upon the information in the prior keys (Figure 1).[vii] In addition to more construction materials, such as concrete, evidence of the Harrisburg’s development into the modern era are also included. Structures used as garages for vehicles are now labelled, as are elevators.
Another helpful note included in Sanborn maps is the roof type. Many historic homes in Harrisburg reflect the Second Empire style and include a mansard roof clad in slate shingles. On Sanborn maps, a dotted line within the building footprint parallel to the front of the building indicates a mansard roof. 800 Green Street has a mansard roof, whereas 802 Green Street does not. The 1929 Sanborn map notates 800 Green Street’s mansard roof (Figure 8). Looking at roof types through Sanborn maps is another way, in addition to construction materials and the count of stories, to identify if the building pictured on the Sanborn map is the same building currently standing.
Access
Luckily for researchers, many Sanborn maps are freely available. All Sanborn maps released prior to 1931 are in the public domain. The Library of Congress, and other archival institutions, provide free access to Sanborn maps in the public domain.
Links to Harrisburg Sanborn Maps
Harrisburg, October 1884: https://www.loc.gov/item/sanborn07707_001/
Harrisburg, August 1890: https://www.loc.gov/item/sanborn07707_002/
Harrisburg, November 1905: https://www.loc.gov/item/sanborn07707_003/
Harrisburg, October 1929 (Volume 1):
https://digital.libraries.psu.edu/digital/collection/maps1/id/28764/rec/4
Harrisburg, October 1929 (Volume 2): https://www.loc.gov/item/sanborn07707_005/
Harrisburg, 1929, republished 1956 (Volume 1): https://www.loc.gov/item/sanborn07707_008/
Harrisburg, 1929, republished 1956 (Volume 2): https://www.loc.gov/item/sanborn07707_009/
Harrisburg, 1929, republished 1956 (Volume 3): https://www.loc.gov/item/sanborn07707_010/
Written by Ericka Kauffman, Historic Preservation Specialist
Published: March 5, 2026
[i] “Sanborn Maps: What They Mean and How They are Made,” August 1960, https://www.cityoffrederickmd.gov/DocumentCenter/View/20242/Sanborn-Maps_How-they-are-made.
[ii] Sanborn Fire Insurance Map from Harrisburg, Dauphin County, Pennsylvania. Sanborn Map Company, Oct, 1884. Map. https://www.loc.gov/item/sanborn07707_001/.
[iii] Sanborn Fire Insurance Map from Harrisburg, Dauphin County, Pennsylvania. Sanborn Map Company, Oct, 1884. Map. https://www.loc.gov/item/sanborn07707_001/.
[iv] Sanborn Fire Insurance Map from Harrisburg, Dauphin County, Pennsylvania. Sanborn Map Company, 1890. Map. https://www.loc.gov/item/sanborn07707_002/.
[v] Sanborn Fire Insurance Map from Harrisburg, Dauphin County, Pennsylvania. Sanborn Map Company, Oct, 1884. Map. https://www.loc.gov/item/sanborn07707_001/.; Sanborn Fire Insurance Map from Harrisburg, Dauphin County, Pennsylvania. Sanborn Map Company, 1890. Map. https://www.loc.gov/item/sanborn07707_002/.
[vi] Sanborn Fire Insurance Map from Harrisburg, Dauphin County, Pennsylvania. Sanborn Map Company, 1905. Map. https://www.loc.gov/item/sanborn07707_003/.
[vii] Sanborn Fire Insurance Map from Harrisburg, Dauphin County, Pennsylvania. Sanborn Map Company, 1929. Map. https://digital.libraries.psu.edu/digital/collection/maps1/id/28764/rec/4.