NARRATIVE: Before Paul Revere could make his famous ride, he had to cross the Charles River to get to Charlestown. The problem was the British had anchored the HMS Somerset in the middle of the river to prevent covert crossings.

Revere and two oarsmen set out from Boston in a small rowboat. Ordinarily, the nearly full moon would have made their passage visible. A particularly southern declination of the moon rise, or perhaps some passing clouds, or a napping sentry on the Somerset, allowed the boat to pass unnoticed.

But for this, maybe nobody would have heard “The shot heard round the world."