On July 20, 1969, Neil Armstrong became the first human being to walk on the moon. As he took his historic last step from the lunar module's ladder and touched the moon's surface (with his left foot), Armstrong famously declared: "That's one small step for man, one giant leap for mankind." The line -- which struck many observers as rather odd -- was supposed to have read: "That's one small step for a man, one giant leap for Mankind."
[Commentators have since suggested that Buzz Aldrin, a more poetic soul, would have made a better choice. His first words on the moon? "Desolation. Magnificent desolation." Incredibly, Armstrong was not officially designated to touch the moon before his mates and an argument arose as they neared the moon. Armstrong was first in part because the hatchway opened into the craft and Aldrin was blocked from approaching the exit!]