When Edison moved to Menlo Park, New Jersey, in spring of 1876 the laboratory building contained his entire operation -- a handful of collaborators, office, library, and machine shop as well as laboratory. As the scale of Edison's investigations grew so did the complex, but this building -- dedicated to experimental activities -- was always understood to be the heart of the enterprise.

This building was built in late 1878 as Edison's work on electric lighting expanded. The first floor provided office space for accounting, bookkeeping, and patent applications; upstairs was a superbly stocked technical library. The building also played another key role: as a reception area for journalists and other visitors it provided a disarming first impression of Edison's success and ambition.

The presence of a machine shop (and of foreman / head machinist John Kruesi) was fundamental to the success of Menlo Park. This well-equipped facility -- built to replace the small machine shop originally installed in the laboratory -- enabled Edison and his associates to not only rapidly prototype iterations of experimental devices but also facilitate their eventual, profitable manufacture.