City planning 15 Statistics 7 Housing 6 Population 6 Census, 1970 4 Economic conditions 4 Census districts 3 more ... Census, 1960 3 Social conditions 3 American Revolution Bicentennial, 1976 2 Census, 1980 2 Description and travel 2 Ethnic groups 2 Historic buildings 2 History 2 Administrative and political divisions 1 Buildings, structures, etc 1 Capital investments 1 Census, 1990 1 Cities and towns 1 Community development 1 Conservation and restoration 1 Economic aspects 1 Education 1 Finance, Public 1 Indexes 1 Local finance 1 Local transit 1 Municipal revenue 1 Municipal services 1 Occupations 1 Penn 1 Planning 1 Population density 1 Tour guides (Manuals) 1 Tourism 1 Tourist information centers 1 Tours 1 Traffic surveys 1 Transportation 1 less ...