Buttelmann was born to German immigrants[1] on June 26, 1929, in Corona, a neighborhood in the New York City borough of Queens.

[3] He began attending the University of Bridgeport in Connecticut in 1948, and he also served as a private in the 514th Troop Carrier Group of the Air National Guard,[4] after having worked as a lifeguard to save for flying lessons.

[8] He was sent to Suwon Air Base, South Korea, on December 23, where he completed several check flights in the F-86 Sabre before doing his first combat mission on January 15, 1953.

[4] On his 50th mission, he came across a formation of MiGs but had to break off because he had reached "bingo" state, which meant he was below the minimum 1,200 pounds (540 kg) of fuel needed to get back to base safely.

Glenn said that "the MiGs' tactics were so poor I could only imagine it was a training flight, or they were low on fuel, but we were unbelievably lucky".

In the F-100 Super Sabre, he flew 232 combat missions while commanding the Misty Forward Air Controllers and the 308th Tactical Fighter Squadron.

[5] In May 2015, he was awarded the Congressional Gold Medal by Nevada Senator Dean Heller for "his role as an American Fighter Ace during the Korean and Vietnam Wars".