Those words endure as one of the best known quotes in the English language.
Some controversy still surrounds his famous quote. The broadcast did not have the "a" in "one small step for a man ... " He and Nasa insisted static had obscured the "a," but after repeated playbacks, he admitted he may have dropped the letter.
Attempts have been made using modern acoustic equipment to search for the missing letter, with one Australian scientist claiming to have found it. Armstrong has expressed a preference, however, that written quotations include the "a" in parentheses.
The Apollo 11 astronauts' euphoric moonwalk provided Americans with a sense of achievement in the space race with Cold War foe the Soviet Union and while Washington was engaged in a bloody war with the communists in Vietnam.
Neil Alden Armstrong was 38 years old at the time and even though he had fulfilled one of mankind's age-old quests that placed him at the pinnacle of human achievement, he did not revel in his accomplishment. He even seemed frustrated by the acclaim it brought.
"I guess we all like to be recognized not for one piece of fireworks but for the ledger of our daily work," Armstrong said in an interview on CBS's "60 Minutes" program in 2005.
He once was asked how he felt knowing his footprints would likely stay on the moon's surface for thousands of years. "I kind of hope that somebody goes up there one of these days and cleans them up," he said.