Port of Philadelphia 5 Shipping--Pennsylvania--Philadelphia 3 Commerce--19th Century 2 Philadelphia (Pa.)--Commerce 2 Coal--Shipping--Philadelphia--20th century 1 Commerce--Philadelphia--19th century 1 Delaware River--Development--20th century 1 more ... Maritime History--Commerce 1 Pennsylvania--Economic conditions--19th century 1 Philadelphia (Pa.)--Commerce--History--19th century 1 Philadelphia (Pa.)--Hog Island 1 Railroads 1 Trade Regulations--19th century 1 Trade and professional associations--Philadelphia (Pa.)--19th century 1 Trade and professional associations--Philadelphia (Pa.)--20th century 1 Trade--Pennsylvania--19th century 1 less ...