It’s from a poem. It’s literary. It was written 60 years after the revolution. It’s also been used to refer to the assassination of Archduke Ferdinand.
There were other rebellions against British rule. The American one was the first successful revolt against a European empire to result in an independent country.
Nope, and plenty did happen sooner.
https://en.wikipedia.org/wiki/List_of_revolutions_and_rebellions#1700%E2%80%931799
Do you mean "the shot heard around the world"?
Yea. Did not any other country before the US ever rise up and say screw you Brits? Or was for some reason we had a better shot? No pun intended.
I'm pretty sure only Americans call it that, and that they do so because they really like mythologising the story of their own founding. How important the event actually was for the rest of the world has nothing to do with it