You are likely familiar with how the British and French fought for control of the confluence in what is now downtown Pittsburgh during the French and Indian War in the 1750s.
Many local battles took place during the war, including the Battle of Jumonville Glen at Fort Necessity (where George Washington is thought to have inadvertently been responsible for starting hostilities), the Braddock Campaign's devastating loss at the Battle of Monongahela, the subsequent victory of the Forbes Campaign taking the confluence for the British (giving us the Pittsburgh we know today from Fort Ligonier to Fort Pitt), and more.
The Battle of Monongahela is memorialized in the appropriately named Braddock and North Braddock, PA, and today you can visit the battlefield site at Braddock's Battlefield History Center at the site of where the battle took place.