The Boston Public Library has five linked exhibits, “Building Boston“, which are free and open to the public:
Building Boston is a citywide celebration of Boston’s public spaces – the architectural and cultural cornerstones that have provided a place for generations to build and share community.
Throughout the city’s long history, our gardens, sports arenas, libraries, courthouses, public transportation centers, and memorials have represented some of the most distinctive and well-known elements of the cityscape. Building Boston explores the stories behind the creation of these iconic public venues, examining the conceivers, constructors, chroniclers, and ever-changing set of users who call these spaces their own.
They’re all interesting, but I think a lot of people will get a kick out of “An Elevated View: The Orange Line” which is about the now defunct elevated section of the Orange Line.