Gone with the Train

Gone with the Train is an historical fiction novel. It is an adventure/action book that begins in Florida when a drought killed many people living there during the early 1920s. Those people that survived the drought fled Florida. Two teenagers in particular, Sally and David, decided to leave Florida without their uncle who they were living with because they did not want to go to North Carolina with him.
Instead, they hopped on a freight train and were missing from their loved ones for about a year and a half.
Towards the end of their dangerous railroad journey, Sally and David were rescued by soldiers and stayed at an Army Post at the United States-Canada Border called Fort Evergreen.
Near the end of the book, David and Sally escaped the soldiers and officers at Fort Evergreen. However, Evergreen soldiers and a private investigator named Ben Wilkens were doing everything they could to find them.
Then in the end, the private eye and soldiers saw the teens in North Carolina but they still couldn't catch them. Once again, Sally and David escaped from the adults, jumped onto a freight train there and were gone with the train.