Final answer:
Gatsby is from North Dakota and fabricates his past including his war service in The Great Gatsby.
Step-by-step explanation:
Gatsby says he's from the midwest, specifically from a place called "San Francisco." However, this is a lie, as Gatsby is actually from North Dakota. He also claims to have participated in World War I and shows a medal that says "Major Jay Gatsby," supposedly given to him by the people of Montenegro for "Valor Extraordinary." While Gatsby is indeed a mysterious character with a fabricated past, the truth about his origins and his war service is gradually revealed throughout the novel.