Only twelve American astronauts have walked on the Moon’s surface, and six of those drove Lunar Roving Vehicles on the Moon. While three astronauts flew to the Moon twice, none of them landed on the Moon more than once. The nine Apollo missions to the Moon occurred between December 1968, and December 1972.

Apart from these 24 people who visited the Moon, no human being has gone beyond low Earth orbit. They have, therefore, been farther from the Earth than anyone else. They are also the only people to have directly viewed the far side of the Moon. The 12 who walked on the Moon are the only people ever to have set foot on an astronomical object other than the Earth.

More Info: en.wikipedia.org