Under Agassiz's management, the Calumet and Hecla mines rapidly increased production, and by 1870 were producing over half of the United States' copper.

[3] The company prospered under his leadership;[3] in particular it underwent substantial growth between 1880 and 1910, when most of these buildings currently standing in the district were built.

[3] Finally, in 1968, the company was purchased by Universal Oil Products,[3] who closed the Keweenaw mines for good.

[6] The original machine shop was designed around 1882 by Erasmus D. Leavitt Jr., a consulting engineer with Calumet & Hecla;[4] it was used to repair large equipment, including mining skips and trams.

[3] A major reconstruction was performed in 1907, and additions were made in 1911; it is likely that the building in its current form dates entirely from these two years.

[7] The roundhouse is built of coursed mine rock masonry in the shape of a semicircle with a turntable in the center.

[4] The structure is built of random mine rock with brick arches over the windows with a shed roof.

[8] The machine shop was roofed by a low gable, and the eaves and construction matched that of the original structure.

[4] Warehouse number 2 was constructed with rail tracks running through it so that large items could be loaded inside.

[4] Both the original boilerhouse and the addition were designed by Erasmus D. Leavit, Jr., and were intended to supply steam to the nearby enginehouse.

[citation needed] The building was purchased in November 2020 by Calumet Electronics and will be renovated to serve as its headquarters.

[14] The Miscowaubik Club was originally built as a private home, reportedly in about 1875 for chief mining engineer Thomas Hoatson.