Fired the Shot Heard Round the World

No cheating-- no googling -- this is a test, and it's not open book.

On this day, in 1803 a famous American poet was born. He penned these words:

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.
The foe long since in silence slept; Alike the conqueror silent sleeps,
And Time the ruined bridge has swept, Down the dark stream that seaward creeps.
On this green bank, by this soft stream, We place with joy a votive stone,
That memory may their deeds redeem, When, like our sires, our sons are gone.
O Thou who made those heroes dare, To die, and leave their children free,
-Bid Time and Nature gently spare, The shaft we raised to them and Thee.

Who is he?

I'll post the answer tomorrow...