When Marcus Daly had a falling out with his business associate in Missoula, A.B. Hammond, Daly decided that Butte needed a store that would compete with Hammond's Missoula Mercantile to sell goods to miners in Butte and lumbermen in Missoula.
He found fellow Irishman and successful businessman, Dan J. Hennessy. Hennessy owned and operated a successful store across the street in the O'Rourke building. The O'Rourke still stands on the corner of Granite and Montana Streets.
With the clout of financial backing from Daly, Hennessy hired architect Frederick Kees of Minneapolis to design one of Uptown Butte's most elegant buildings.
The cast iron storefront was a common feature for commercial buildings in Butte but Hennessy's is more ornate than others with ornamental leaded glass, archway entrance, and wrought iron grillwork.
The red terra cotta brick of the exterior walls is draped over a steel frame. Ornate terra cotta trim designs embellish the exterior windows and walls and doorways.
The store opened for business in 1898. Inside the store, shoppers found marble staircases, oak counters, and solid bronze balustrades. They also found every type of merchandise they might imagine in 17 departments that filled the basement level and the first three floors. When it opened, the store employed 200 people.
In 1901, the Anaconda Company moved its offices to the top floor of the building and from there decisions were made that affected the fortune of the state and had an impact on financial markets around the world.