benignum and redleg, Nixon didn’t end the Vietnam War. The North Vietnamese ended it when they won the war. It was Gerald Ford who announced the end of American involvement in Vietnam (and under whose watch Americans were evacuated from Saigon).
CTL, I worked with a guy who used both II and Jr. Maybe his great grandfather was Ploni Almoni and his father was named Ploni Almoni II, making my coworker Ploni Almoni II Jr.