Who is John Sidney McCain Senior from Faith of My Fathers and what is their importance?

John Sidney McCain Senior was a naval aviator who became a four-star admiral. John McCain, his grandson, remembers him as a slight, gaunt, hawk-faced man, who was rail-thin and had a low timbre voice. He was a chain smoker and was notorious for living large.

A natural born leader, McCain Senior succeeded because of his respect for those under his command. He was a brave in combat, put all of his energy into his fighting, and died shortly after the end of World War II.