Greater Philadelphia Geo History Network

This is a great site that has the modern day google map of Philadelphia but on the side you can click a number of different years to have a historical map on top of the modern map. I use it all the time as a genealogist that specializes in this area but it’s also a good tool for stuff like OP is mentioning like former bodies of water and also stuff like former cemeteries, former factories (to see if crazy chemicals might be in the ground) and other maybe cool maybe not so cool stuff lol