Abstract The Montana Ore Purchasing Company was a Butte, Montana, mining and smelting company owned by F. Augustus Heinze and John MacGinnis. The company was involved in a long court fight with the Anaconda Copper Mining Company, known as the "War of the Copper Kings." Records include incoming correspondence (1900-1910), outgoing correspondence (1905-1906), court papers, daily smelter reports (August 1905), two journals (1905), an order book (1905-1906), legal documents, and miscellany. There is a...