Industrial Research Laboratory
In March 1876, after working in Newark, N.J., for five years, Thomas Edison relocated his base of operations to Menlo Park. Though the young inventor had already secured patents for a wide variety of devices, the period he spent working out of the two-story structure in rural New Jersey, above, would prove to be particularly productive. In the six years he and his associates worked there, more than 400 patents were obtained.

• Thomas Edison and the Making of America