His real name was always John. "Jack" is a standard nickname for John, comparable to Dick for Richard and Hank for Henry.
Joseph Patrick "Joe" Kennedy Sr. President John kennedys fathers name was John, he was Johnsr.
His full name was John Fitzgerald Kennedy.
Macaroni
Fitzgerald Kennedy.
Rose Fitzgerald.
Macaroni
Jacqueline Bouvier
his boat name was the PT-109 and he was the captain of it!
Her name was Rose Elizabeth Fitzgerald Kennedy (1890-1995).
The name Jack is a derivation of the name John.
The name Jack can be short for James, John, Jonathan, or Jacob.
His birth name was John Joseph Nicholson and Jack is another name for John.