Butte, Montana got its start as a mining boom town. Immigrants started pouring in the area in the 1860s, but it was mostly placer mining until it started to dry up in 1871, and it wasn’t until 1874 when hard rock mining started to gain traction.Not unlike most boom towns in the frontier west, Butte initially got its attraction for its gold and silver, but the newfound harness of electricity created a huge demand for copper, which Butte was more than abundant in.
By 1882, the district produced about nine million pounds of copper, and doubled that by the following years. By 1884, there were four smelters and the largest metallurgic plant was starting to be built by the Anaconda company. Five square miles of Butte ended up producing about 210 million pounds of copper a year.
The copper industry was being ruled by three moguls, also known as the “Copper Kings”. Marcus Daly, F. Augustus Heinze, and W. A. Clark were the top mining magnates that rivaled each other, which was also known as “The War of the Copper Kings”. This “war” was put to an end after the Amalgamated Copper Company absorbed all of their holdings, and was re-dubbed the Anaconda Copper Mining Company.
The Anaconda company was buying mines left and right, and became overwhelmingly powerful. Because it was so profitable, it was able to turn low grade ore mines, and turn them into open pits. The logic of this method was to process large quantities of ore at a time. The Berkley Pit processed 30,000 tons a day by 1963. 
Since butte was a massive boom town, it became a massive melting pot for immigrants from all over, especially in the mining community,
Cultural groups within Butte retained their traditions, their food, their religious celebrations and decorations, and their ethnic slurs for one another. But “below ground” there were no distinctions. And everyone understood that. Everyone knew that when trouble came, we were all family. There were no distinctions.
Since Montana was a separate territory at the time, a common saying was “Don’t stop at America, head to Butte.” Many immigrants would arrive to Ellis and head straight to Butte,
Butte was such a hot spot during the last great world migration at the turn of the twentieth century, that people arrived at Ellis Island with Butte, America pinned to their shirts. Butte absorbed the best from every culture, learned to get along, enriched its inhabitants with a kaleidoscope of tastes, traditions and languages, and ultimately rose above it all to be become a unified city. 
Not only was butte a cultural melting pot, it was also a hotbed for worker’s rights for mining. The Granite Mountain mining tragedy triggered the need for safety regulations, which gave awareness for mining safety, as well as giving the US Bureau of Mines a world authority for mining safety. This was derivative to the mining safety standards we have today.
Butte also pioneered unionization for workers,
The consolidation of mining interests placed heavy demands on the immigrant workers who toiled in the mines under harsh conditions. This situation led Butte to the forefront of labor organization and unionism, and it was one of the first cities in the world where the battle between labor and management played out.
Because open pits mining is less labor intensive, the work force demand dwindled. On top of that, the Anaconda Mine was losing its international mine to nationalization, along with bad investments, the company was sold to ARCO(Atlantic Richfield) in 1977. ARCO stopped all operations in 1983. The only thing left of the Anaconda smelter is its smokestack. By the 1990s, the population declined to about 32,000 people from its peak of 60,000 in 1920.
This city was once considered “The richest hill in the world”, because such a small area was producing an insane amount of money. I think a lot of it had to do with the heavy demand of copper at the time, as well as the entrepreneurial spirit of the frontiersmen. Since Butte was such a draw, it became massively diverse, giving Butte a rich and culturally profound history.
The Copper Kings
Butte back in the day