Born in the small eastern Ohio town of Cambridge on July 18, 1921, Glenn recounted an idyllic childhood where "patriotism filled the air."

 

"Love of country was a given. Defense of its ideals was an obligation," Glenn wrote in his memoir. "The opportunity to join in its quests and explorations was a challenge not only to fulfill a sacred duty but to join a joyous adventure."

 

Glenn developed a fascination with flying at an early age. When he was 8 years old, he and his father went for a ride in an open-cockpit biplane, two years after Charles Lindbergh made his transatlantic flight. That adventure sealed his destiny as a future pilot.

 

He also developed an early love for childhood playmate Anna Margaret Castor. By the time they got to high school, they were sweethearts. Both were in Muskingum College in New Concord, his mother's alma mater, when Japanese forces attacked Pearl Harbor on December 7, 1941. A short time later, Glenn enrolled in the Naval Aviation Cadet Program and graduated the following March. He joined the Marine Corps in early 1943, and wed his childhood sweetheart on April 6 of that year.

 

Glenn flew 149 combat missions in World War II and the Korean War. In the final nine days of the Korean War, Glenn shot down three MiG fighter jets along the Yalu River. His military service earned him numerous awards, including six Distinguished Flying Crosses.

 

After Korea, Glenn became a test pilot for Naval and Marine aircraft and, in 1957, set the transcontinental air speed record. He flew a Vought F-8 Crusader from Los Angeles to New York in 3 hours and 23 minutes -- the first transcontinental flight to average supersonic speed.

 

With that feat, Glenn became known as one of the top test pilots in the United States and a natural candidate for the country's emerging space program.