"The Enigma Of Grover's Mill", Bradford Morrow

Wyatt grows up in Grover's Mill, the city of H.G. Wells and Orson Welles' War Of The Worlds. His father, a Great War veteran, can't face another war and kills himself rather than fight aliens. Soon his mother and grandfather die. Wyatt is convinced that Franklin, a boarder who comes to live with his grandmother and him, is an alien who survived when his s side lost the invasion.