Pennsylvania Historic Preservation

Blog of the Pennsylvania State Historic Preservation Office

Using Pennsylvania’s Agricultural Context in the Field and on the Farm: Tips, Tricks, and Updates


The ambitious Pennsylvania Agricultural History Project started in 2001 and took 12 years to finish. 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, cultural 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.

**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.

Updates include:

  • Guidance for understanding farm production after 1927 (oral interview questions and interpretation for historic aerial views).
  • Worksheets outlining registration requirements for identified regions and time periods, including 1960 to 1980.
  • Model Historic Resource Survey Forms for farms.

Resources Constructed between 1960 and 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.

This guidance is found in Additional Guidance for Agricultural Resources of Pennsylvania MPDF: Agricultural Resources of Pennsylvania, c1960-1980: An Era of Specialization and Expanded Amish Presence.

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.

Oral History Questions

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.

The questions are included as Appendix A in Additional Guidance for Using PA’s Agricultural Context, May 2019.

Tutorial for Historic Aerial Photographs

Dr. McMurry also prepared a detailed tutorial on how to interpret farm production using historic aerials from the 1930s to the 1970s. Aerial mapping was flown statewide for the U.S. Department of Agriculture, Agricultural Adjustment Administration (now the Farm Service Agency) and is available on the PennPilot website: More recent aerial mapping is also available through Pennsylvania Spatial Data Access (PASDA).

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.

Example of a PennPilot aerial from June 1958.

This tutorial is included as Appendix B in Additional Guidance for Using PA’s Agricultural Context, May 2019.

Registration Requirements 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.

The worksheets include a list of required attachments:

  • 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. 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 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. 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.

The worksheets are included as Appendix C in Additional Guidance for Using PA’s Agricultural Context, May 2019.

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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