Lexington & Concord - I found the following on the corresponding Wikipedia page:

Ralph Waldo Emerson describes the first shot fired by the Patriots at the North Bridge in his "Concord Hymn" as the "shot heard round the world".

"By the rude bridge that arched the flood
Their flag to April's breeze unfurled
Here once the embattled farmers stood
And fired the shot heard round the world."

• First verse of Emerson's "Concord Hymn"

"Reflecting on the British experience that day, Earl Percy understood the significance of the American tactics:

During the whole affair the Rebels attacked us in a very scattered, irregular manner, but with perseverance & resolution, nor did they ever dare to form into any regular body. Indeed, they knew too well what was proper, to do so.

Whoever looks upon them as an irregular mob, will find himself much mistaken. They have men amongst them who know very well what they are about, having been employed as Rangers against the Indians & Canadians, & this country being much covered with wood, and hilly, is very advantageous for their method of fighting."

Years?