Pittsburgh is a city of about 350,000 in Allegheny County, at the center of the Pittsburgh Region in southwestern Pennsylvania; the population of its metropolitan area is about 2.4 million. It is situated at the confluence of the Monongahela and Allegheny Rivers, which meet to form the Ohio River. Pittsburgh's unique terrain has resulted in an unusual city design and a hodge-podge of unique neighborhood "pockets" with diverse ethnic and architectural heritage. Pittsburgh has a rich history and, for its size, an unusual array of cultural treasures, largely thanks to the wealth that was generated when Pittsburgh was a hub of industry.
The first European to "discover" the site of Pittsburgh was French discoverer/trader Sieur de La Salle in his 1669 expedition. The settlement of Pittsburgh began as a strategic point at the confluence of three rivers, with Britain, France, and the local Native American tribes all vying for control over this spot and thus, the region. On what is now referred to as The Point, where the rivers meet, several forts were constructed by competing French and British forces during the French and Indian War. In 1758, British general John Forbes ordered the construction of Fort Pitt, named after British Secretary of State William Pitt the Elder. He also named the settlement between the rivers "Pittsborough". Manufacturing in Pittsburgh began in earnest in the early 19th century, and by the US Civil War the city was known as "the armory of the Union." This began a sharp escalation of industry, particularly steel and glass. By the late 19th century, Pittsburgh was known as the Steel City. Andrew Carnegie began the Carnegie Steel Company in 1892, which became United States Steel (USS) a decade later and grew to be the largest corporation of any kind in the world. Carnegie became the richest man on Earth and, along with other local magnates of industry, gave Pittsburgh cultural institutions such as the Carnegie Museums, Carnegie Library, and Carnegie-Mellon University. A number of other Fortune 100 companies have called Pittsburgh their headquarters, helping fund world-class museums, theaters, universities, and other attractions.