In Milkweed by Jerry Spinelli, the protagonist (later named Misha) is orphaned and must determine an identity for himself even though he does not know where he has come from or what his cultural identity actually is.  While foraging and trying to survive, Misha becomes friends with a girl named Janina and eventually goes with her and her family to a resettlement area when they are forced into the Warsaw ghetto.  Misha, Janina, and her family must navigate the grueling landscape of the ghetto, and life becomes even more despairing when they realize that they must remain in the ghetto.