Philadelphia
Delaware river, and Schuylkill river.
Philadelphia
No it wasn't. Colonial Pennsylvania is about half the size of Pennsylvania today
New York City was the most important port city in New York. No other colonial city had more trade. Philadelphia and Boston in Pennsylvania and Massachusetts respectively were second and third. No other New York city was close to the importance of NYC.
Harrisburg
In Pennsylvania
In 1775 there was no State of Pennsylvania. Pennsylvania was still a British colony. Pennsylvania was largly a colony of farming communities with a significant, and largely unsettled, western frontier. It also had Philadelphia, the largest city in the English North Ameican colonies and a major trading port.
The address of the Colonial Drake Cultural Alliance Inc is: Seneca St, Oil City, PA 16301
New York City
Yes it's true, the city of Philadelphia did exist in colonial America (specifically, in the colony of Pennsylvania) and it continues to exist even now, in the year 2013.
Trenton
One major city was Wilmington.