This fort sits at the junction of the Allegheny and Monongahela rivers - essentially the beginning of the Ohio River. In 1754, the French and British governments were fighting over who controlled the territory in the area. When settlers from Virginia began to build a fort, French Canadian forces chased them out, which is weird, because Canadians are usually so polite. Anyway, they finished the fort, which was nice of them, and named it after the then-governor of New France, the Marquis Duquesne, which was wonderfully thoughtful.
In response, the British colonial government sent George Washington to re-take the fort (at the Battle of Fort Necessity), and then Edward Braddock (the Braddock Expedition). Both attempts failed miserably, each being defeated before they ever reached the fort.
Fort Duquesne remained under French control until 1758, when the French troops abandoned and burned it. The British moved in and rebuilt it, naming the new construction 'Fort Pitt' - the location of modern-day Pittsburgh, which makes me think maybe they shouldn't have bothered.