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2019 Updates to PA’s Agricultural History Project


This post contains updates  to the statewide agricultural context, also known as the Pennsylvania Agricultural History Project, through May 2019. The updates include the following components which are provided in the document 2019 Updates to PA Agricultural History Project – Additional Guidance for Using Pennsylvania’s Agricultural Context:

Required Attachments. As part of efforts to improve documentation of farms, SHPO will be requiring the following attachments for farms and/or farmsteads documented on Resource Survey Forms:

  • Site plan with buildings labeled and dated
  • Photo location map (can be part of site plan)
  • Historic aerials containing both a zoomed in and zoomed out picture with labeling of buildings that remain and have been lost.
  • Presentation of agricultural census data comparison both graphically and numerically on a scale that is readable.
  • Agricultural assessment worksheets.

Agricultural Assessment Worksheets. The worksheets are to be provided as an attachment to the HRSF. Their purpose is to summarize the registration requirements for the identified regions and time periods, including 1960 to 1980. These worksheets are included as Appendix A in the Update Guidance document.

Determining Farm Production Levels After 1927: Oral Interviews, Aerial Comparisons, and Comparative Property Types. After 1927, U.S Agricultural Census data is not available at the farm level. Oral interviews and a careful comparison of historic and current aerial mapping can help to determine production levels for this period. If necessary, they can be supplemented by a comparison of similar property types in the surrounding area.

A sample list of questions to ask when conducting oral interviews with current or former farm owners or operators is available in Appendix B of Additional Guidance. Guidance for interpreting historic aerial photographs to determine farm production is available in Appendix C of the same document.

Model Historic Resource Survey Forms for Farms. These forms are found in the Additional Guidance document and should be referenced to understand how graphics and census data should be presented.

Two additional documents were developed as part of the update:

Agriculture Resource of Pennsylvania, c. 1960-1980. Includes a narrative history and registration requirements for primary agricultural products for farms between 1960 and 1980. Regionalized diversification in agricultural production largely disappeared in this period so the focus is on how the built environment and landscape reflect statewide agricultural trends. Due to the growth of the Plain Sect, largely Amish population, in this period and their ties to agrarian lifestyles, an additional cultural/religious group and related property type are also recognized.  

Updates to the Statement of Integrity. The updates to the statement of integrity address alterations on the Plain Sect (Amish) farmstead and new construction within the farm plan.


Please note the purpose of the update is to provide needed clarification for determination of eligibility; the update is not a formal update to the MPDF but an evolving and ongoing effort to provide continual guidance updates to benefit our staff and regular users of the context.

History of the Pennsylvania Agricultural History Project

As outlined in a past posting, the ambitious Pennsylvania Agricultural History Project was begun in 2001 and completed in 2013. The project included the creation of a statewide agricultural context for the National Register evaluation of agricultural properties, entitled “Agricultural Resources of Pennsylvania, 1700-1960, Multiple Property Documentation Form (MPDF)”.

Sixteen agricultural regions were identified based on factors such as product mix, labor and mechanization, tenancy, culture and ethnicity. Separate contexts, property types, and registration requirements were developed for each of the agricultural regions.

The statewide agricultural context allows for more consistent and expeditious National Register eligibility evaluations (over 1,900 so far). Most of these resources (approximately 1,800) have been evaluated as a result of the Section 106 and State History Code review processes.

Over the course of the last six years, SHPO and PennDOT staff have recognized a need to provide more tools and guidance for implementation of the context, especially addressing post-1960 changes to farms. As a result, a joint effort was undertaken in 2017-2019, once again involving a partnership between the Pennsylvania Historical and Museum Commission, the Pennsylvania Department of Transportation, and Dr. Sally McMurry of Pennsylvania State University with funding from the Federal Highway Administration.

More about the 2019 Updates

Determining Farm Production Levels After 1927

For those years U.S. Agricultural Census data is available (1850, 1880, 1927), the statewide agricultural context recommends using federal census data as a clue in determining if a farm exhibits regional trends.  This involves a comparison of an individual farm’s production to the average production level of farms in the township at the time.

Unfortunately, after 1927, census data on agricultural production is not available at the individual farm level. Thus, we saw a need for additional guidance to help researchers assess production trends for agricultural properties operating after 1927.

Interviewing current or former farm occupants can provide valuable insights into the farm’s evolution and production. As part of this update, a list of essential questions was developed by Dr. McMurry. The questions focus on agricultural production and changes to the farm complex and landscape in recent memory.

She also prepared a detailed tutorial on how to interpret farm production using historic aerials from the 1930s to the 1970s. Aerial photographs covering the Commonwealth were taken for the U.S. Department of Agriculture from 1937-1972 and are available on the PennPilot website:

Example of a PennPilot aerial from June 1958.

More recent aerial mapping is also available through Pennsylvania Spatial Data Access (PASDA) at Comparing the historic aerial photos to recent aerial imagery helps clarify how—and how much—a farm’s landscape has evolved and point to changes in the farm’s production, equipment, and technology as well as local economic and development patterns that impact farms. These photographs are essential tools and readily available online for most parts of Pennsylvania.

When the former farm owner or producer is not available to answer questions on production or an examination of historic aerials doesn’t yield enough information, comparative property types is another tool that can be used. In this period farms with buildings larger in number and size tend to reflect high levers of production. Compare how the 50-year-old buildings that make up the farmstead compares to neighboring farmsteads. A maximum of a one-mile radius should be used for comparative property types.

Required Attachments to HRSFs

To ensure consistent and effective documentation, SHPO is now requiring the following attachments to Resource Survey Forms for farms and farmsteads:

  • Site plans. Current aerial photograph with buildings labeled (historic function and date of construction and/or additions) and landscape features noted, with a caption beneath the image. If possible, less than 50-year-old buildings and features should be visually identified with hatching or different colorization. Include the outline of the farm (including all associated tax parcels if the farm is not a single parcel).
  • Photo location map (can be part of the current aerial site plan).
  • Historic aerials with changes to the built environment and landscape features (i.e. demolitions, additions, moved buildings) labeled and dated, with a caption beneath the image that includes the year of the image and calls attention to substantial changes to the landscape. If available, include an outline of the farm’s boundary at that time.
  • Comparison of 1850, 1880 and 1927 agricultural census data for the farm and township averages. Census data should be presented in chart form both graphically and numerically.
  • Agricultural Assessment Worksheets

Agricultural Assessment Worksheets

To help users manage and process the substantial information presented in the context’s original and updated narratives and registration requirements, worksheets were developed for each region and the related specific time periods. Completed worksheets are to be submitted with each Historic Resource Survey Form prepared for farms and act as a sort of checklist for preparers—but are not to replace a thorough examination and application of the relevant narrative for each region.

Agricultural Resources of Pennsylvania c. 1960-1980

As Section 106 review requires consideration of those resources 50 years in age or older, it was critical to develop National Register evaluation guidance for resources constructed after 1960. Unlike the pre-1960 period, which was characterized by diversified, small family farms, the 1960-1980 narrative and registration requirements explains the trend of this period was toward specialized production, on both small- and large-scale farms.

Conventional Stall barn, 1955.

As regionalization of building types largely disappears from the landscape after 1960, the context for this period does not include a regional specialization (except for orchard and vineyard production). The registration requirements for the period are organized around common agricultural products that were found across Pennsylvania including dairy, livestock, poultry, and cash grain/hay. Due to the growth of the Plain Sect population in this period and their ties to agrarian lifestyles, an additional cultural/religious group and related property types are recognized.

Statement of Integrity Updates

Finally,  May 2019 Updates to the Statement of Integrity address alterations on the Plain Sect (Amish) farmstead and new construction within the farm plan.

What do you think?

Please try using these tools to see if they help you apply the statewide agricultural context, especially when it comes to 20th century changes. Please be sure to let us know what you think so we can continue to provide meaningful updates and improvements.

Author: Barbara Frederick

Barbara Frederick is a historic structures reviewer for the PHMC-BHP. She is responsible for reviewing project documents submitted in compliance with Section 106 and the State History Code for the eastern region of Pennsylvania.


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