In 1873, John Lane Buell exposed one of the richest deposits of iron ore in the world. His discovery, known as the Menominee Iron Range, led to the development of the area and the subsequent creation of Dickinson County in 1891. The last of Michigan's eighty-three counties to be organized, it was named for Donald Dickinson, a prominent Detroit attorney and postmaster general in the first administration of President Grover Cleveland (1885 - 1889). Three of Michigan's largest iron mines were located in Iron Mountain, which had an abundant supply of water power and was served by two major railroads. Iron Mountain became a center of commerce and distribution for the range and was the natural location for the county seat once the county organized.