PLEASE HELP He said to his friend, “If the British march

By land or sea from the town to-night,

Hang a lantern aloft in the belfry-arch

Of the North-Church-tower, as a signal-light,--

One if by land, and two if by sea;

And I on the opposite shore will be,

Ready to ride and spread the alarm

Through every Middlesex village and farm,

For the country-folk to be up and to arm.”

-Henry Wadsworth Longfellow

To which historical era does the event being described in the excerpt above belong?