Internal improvements 4 Canals 3 Internal Improvements--18th century 3 Railroads 3 Internal Improvements--19th century 2 Bridges--Pennsylvania--19th century 1 Built Enviroment--Philadelphia--19th century 1 more ... Built Environment--Philadelphia--18th century 1 Built environment--Pennsylvania--Philadelphia--20th century 1 Costs 1 Early works to 1850 1 Internal Improvements--Bridges--Pennsylvania 1 Internal Improvements--Canals--Delaware 1 Internal Improvements--Canals--Maryland 1 Internal Improvements--Canals--Pennsylvania 1 Internal improvement 1 Investment--19th Century 1 Land Settlements--Pennsylvania 1 Land Surveys--18th century 1 Maintenance and repair 1 McCall's Ferry--Lancaster County (Pa.)--19th century 1 Municipal Government--Philadelphia--18th century 1 Philadelphia Views--18th century 1 Philadelphia--Built Environment--Images 1 Women's History--Service organizations 1 less ...