"That's one small step for man, one giant leap for mankind."

Anyone old enough to remember will likely tell you exactly where they were when NASA astronaut Neil Armstrong declared those words as he stepped foot on the surface of the moon on .

It was an unprecedented moment in history that was watched live on television by an estimated 600 million people and celebrated by millions more around the world.

The United States had entered the space race in May 1961, when U.S President John F. Kennedy appealed to the nation during a special joint session of Congress with an epic challenge: land a man on the moon and return him safely to Earth before the end of the decade.

Fifty years later, the moon landing is still considered one of the most important achievements in human history.

It is also considered by many to be the pinnacle of the Cold War-era space race that pitted the United States against the former Soviet Union (U.S.S.R.) -- two countries locked in an intense competition for total space domination.

While it was the U.S. that ended up earning the bragging rights for putting the first human on the moon, they were spurred on by the U.S.S.R. racking up many other space-race firsts.

From launching the first intercontinental ballistic missile (August 1957) and satellite (October 1957), to putting the first woman (June 1963) in space, the U.S.S.R. was pushing to beat the U.S. in all aspects of space flight.

KEY MOMENTS

The intense rivalry resulted in major for both countries.

June 11, 1948: A rhesus macaque named Albert was the first of many primates the U.S. sent into space to test the biological impacts of space travel.

October 4, 1957: The U.S.S.R. successfully launched Sputnik 1, the first satellite, into space.

April 12, 1961: Russian cosmonaut Yuri Gagarin became the first human to go into outer space. U.S. astronaut Alan Shepard became the second person and the first American to do the same, about a month later.

June 16, 1963: Former Russian cosmonaut Valentina Tereshkova became the first woman to fly in space. The 1963 mission also made her the only woman to have flown to space solo.

July 20, 1969: Apollo 11 astronauts and Buzz Aldrin became the first humans to land on the moon. Armstrong's first steps on the lunar surface were broadcast live on TV to a global audience.

FACT OR FICTION?

Like many pivotal moments in history, the moon landing isn’t immune to wild . Many stories are still being widely shared that claim the moon landing was faked and never happened. 

Doubters point to so-called discrepancies in the video of the lunar landing that they say confirms the U.S. government staged the entire event just to say they beat the U.S.S.R.