Street map of Reading, Pennsylvania, 1872
Drainage area plan, early 19th century
Dripps map of Frankford and vicinity, 1849
Darby, Delaware County, Pennsylvania, 1877
Ground Plan, Great Central Sanitary Fair, Philadelphia
Images from ‘The Water Supply of the City of Philadelphia by a proposed Aqueduct from Norristown Dam’
“A Snake That Will Be Straightened Out,” map of Frankford Creek with proposed changes, 1949
Plan of the City of Philadelphia and Adjoining Districts, 1830
Map of Philadelphia showing Population in year 1920
Map of the County of Philadelphia from Actual Survey, 1843