Simplify the following text for a Grade 9 native English-speaking person.
Original: He joined in the United States Marine Corps in 1963 , and served as a Marine in the Vietnam War , where he was seriously injured in 1965 near Da Nang -- his right arm shattered and partially paralyzed .
Simplified: He enlisted in the United States Marine Corps in 1963 , and served as a Marine in the Vietnam War , reaching the rank of Corporal . He was seriously injured in 1965 near Da Nang -- his right arm shattered and partially paralyzed .