There are 2 achievements for the remaining episodes that reference the water. In episode 3, the 2nd Act is reffered to as “Shoreline”. For the 4th episode, the 1st achievement is “Red Water”.
On the map that Marlon gave us from Episode 1, there is a HUGE river practically beside the Boarding School.
My best guess is that we are following Lilly along that river to get the other kids. James told us the War is between Lilly’s entire community and another one “In the North”.
A direction may not be the most detailed clue, but it’s safe to asume that it is a considerable distance away. This is helped by the fact that James left the Whisperers, who were next to Washington DC, also the home of Rick and co.
For someone just wandering around, James knows a lot about this war and the practices of at least one side.
Sophie and Minnie were taken a year ago, indicating this engagement has been going on for at least a year. Conflicts can only be drawn out based on manpower; if even just 1 person died per day, this war must have already seen hundreds of casualities, if not thousands. This is a war on a much larger scale than we’ve ever seen before in the Walking Dead universe. Hype.
With that out of the way, I believe this river is the Potomac River.
Why is this important to know? Because..it leads right to where New Alexandria is. I think Lily’s group is at war with Rick and the combined strength of New Alexandria, Hilltop, Kingdom, and the Sanctuary. There is enough people across here to sustain such a long conflict.