The second city of Pennsylvania in population and importance. Occupies the delta between the Alleghany and Monongahela Rivers which here join to form the Ohio. This is the site of the old French Fort du Quesne, famous in colonial annals. On its capture by the British the name became Fort Pitt, in honor of the Prime Minister, hence Pittsburg. Several popular suburbs are connected with Pittsburg by many artistic bridges which span the Alleghany and Monongahela Rivers. 10.