Neil Armstrong

That’s one small step for [a] man, one giant leap for mankind.

What the Apollo 11 astronaut said as he set foot upon the lunar surface on July 21, 1969. The sentence is self-contradictory as CBS news anchor Walter Cronkite heard it and repeated it on air, without the indefinite article — “man,” unmodified, in this context means “mankind” — but Armstrong had indeed intended to say it with the article, so making his announcement sensible and even profound; it is also what he probably did actually say, but was garbled in the transmission to Earth.