Pittsburgh, although located in Pennsylvania and therefore considered part of to the Mid-Atlantic region in our division, is actually west of the Appalachians, at a strategic point where two smaller rivers form the Ohio River. So geographically it should be considered part of the east Midwest. It has a lot in common with other major cities in the Great Lakes area, such as Cleveland or Detroit, since Pittsburgh grew large in the late 19th century as a result of industrialization. From the 1860s to the 1960s, it was known as the "Steel City", because it produced the largest amount of steel in the US, based on the coal mines of western Pennsylvania.  The city attracted many immigrants at the turn of the 19th and 20th centuries, including a significant number of Hungarians. When traditional heavy industries collapsed in the 1970s and 80s, Pittsburgh suffered too, losing half of its population compared to 1950. Nowadays, the city is based on a more diverse economy.