The city of Pittsburgh was founded in 1758 when the British took Fort Duquesne from the French at the height of the Seven Years’ War. On the site of a former French fortification, British forces constructed Fort Pitt around 1764 under the orders of General John Forbes. At the time, it was one of the largest and most elaborate forts in North America. Eventually, the fort was decommissioned by the British and used as a trading post 

Later, a series of four blockhouses were constructed around the fort. After the Revolutionary War, the fort was decommissioned and only one blockhouse still stands today.