In the 1970s, Massachusetts commanded all cities and towns in the state to set up Historical Commissions.  Many already had Historical "Societies", but those are not a part of a municipal government.  The Secretary of State's office oversees the Mass Historic Commission and they developed a series of templates for writing historic narratives about specific properties. The cities and town were then directed to use them and develop a database of all the historic properties in the Commonwealth. 

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Let's look at the town of Billerica where the old B&M RR (now Pan Am Railways) had a huge presence. Something like 600 acres with a huge yard, maintenance facilities etc. B&M sold off huge swaths of assets to Mass. (managed by the MBTA) that include much of the built environment at Iron Horse Park.  

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In Billerica, they have over 450 historic places on the list.  Over 30 alone are related to the B&M RR's facilities in Iron Horse Park.  Below is a screenshot of one of the pages detailing the railroad infrastructure.  At the very bottom is one of the write-ups.  Done by a consultant for the MBTA.  Note: The Form Bs are not encompassing--they wet the appetite so to speak. 

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