Young Jack (left, center) with half brothers Patrick and Gregory in Key West, Florida; and at age three with his father at a Schruns, Austria, ski resort (right). Ernest Hemingway Photograph Collection/John F. Kennedy Presidential Library and Museum, Boston

Ernest Hemingway Photograph Collection/John F. Kennedy Presidential Library and Museum, Boston (Ernest Hemingway Photograph Collection/John F. Kennedy Presidential Library and Museum, Boston)

Ernest Hemingway Photograph Collection/John F. Kennedy Presidential Library and Museum, Boston