The Confederacy coveted Pittsburgh while the Union had its eyes set on the Hornets Nest of Charlotte. Neither achieved their goals.
Although there were certainly fortifications dug to prepare Pittsburgh for a Confederate assault. The ruins of one can be found not far from where I grew up. The local garrison commander was authorized to hire “as many men as necessary” to dig them. Reportedly a lot of them did not get paid. Some of their families were still trying to collect from the Federal Government as late as the 1970’s.