Another gem from the USGS store.
This thumbnail shows the long-abandoned Roswell Branch of the Southern Railway where it joins the main line in Chamblee. Click to get a much larger map covering a much larger area.
Notice that most of the Chattahoochee are still ferries on this map, rather than bridges. Holcomb Ferry is located more or less where Holcomb Bridge road is now, and so are the others.
The Eastern Continental Divide is rather easier to see on this map than on a modern map, if you know where to look.