Query: What was John Eisenhower's final rank in the military?
Context: Their second son, John Eisenhower (1922–2013), was born in Denver Colorado. John served in the United States Army, retired as a brigadier general, became an author and served as U.S. Ambassador to Belgium from 1969 to 1971. Coincidentally, John graduated from West Point on D-Day, June 6, 1944.