A Sound of Thunder

Most Republished SF Short Story EVER by Ray Bradbury

Available all over the internet and in random anthologies.

Entire premise is summed up by a sign in the second sentence:

TIME SAFARI, INC.

SAFARIS TO ANY YEAR IN THE PAST.
YOU NAME THE ANIMAL.
WE TAKE YOU THERE.
YOU SHOOT IT.

The time travel is H.G. Wells style and the safari guides go to some length describing what precautions they take against changing the future. But the emphasis on not leaving the path seems a bit weird, considering that the falling dead dinosaurs are going to kill far more bugs and blades of grass. But that's just Fridge Logic.

In the 58 years since this was published, tons of other stories have played on the same themes and had similar plots. But this was the start of a lot of common time travel tropes, and established the fiction version of the Butterfly Effect years before Chaos Theory existed. So seeing all that together is still neat, and if you ignore the biology the story ages quite well.

The biggest difference though, is that Bradbury wrote a better sounding time travel story than the millions he inspired here. I just love the description in places:

The jungle was high and the jungle was broad and the jungle was the entire world forever and forever. Sounds like music and sounds like flying tents filled the sky, and those were pterodactyls soaring with cavernous gray wings, gigantic bats of delirium and night fever.

Or possibly:

The Monster twitched its jeweler’s hands down to fondle at the men, to twist them in half, to crush them like berries, to cram them into its teeth and its screaming throat.

But the coolest (and oddly still original feeling after all these years) part of the story is that when our adventurers inevitably change things, they find out that they cannot be fixed. This kind of non-wimp ending seems to be rare in all the copycat stories that came after. Since it is the strongest part, I'm not really sure why.

So I loved this story and always have. 5 historically significant butterflies out of 5.

P.S. If this story were published today, I'm sure people would say the awful presidential candidate was a thinly veiled reference to George W. Bush. And if it had been published 20 years ago, they'd have compared him to Reagan. But Ray Bradbury was hating on anti-intellectual politics before it was cool.