Let tyrants shake their iron rod,Those lyrics are by William Billings, but date from 1778, not (obviously) when he first published the tune, in 1770.
And Slav'ry clank her galling chains,
We fear them not, we trust in God,
New England's God forever reigns.
Howe and Burgoyne and Clinton too,
With Prescot and Cornwallis join'd,
Together plot our Overthrow,
In one Infernal league combin'd.
When God inspir'd us for the fight,
Their ranks were broke, their lines were forc'd,
Their ships were Shatter'd in our sight,
Or swiftly driven from our Coast.
The Foe comes on with haughty Stride;
Our troops advance with martial noise,
Their Vet'rans flee before our Youth,
And Gen'rals yield to beardless Boys.
What grateful Off'ring shall we bring?
What shall we render to the Lord?
Loud Halleluiahs let us Sing,
And praise his name on ev'ry Chord.
So it was being sung in 1776, just not like this.
Not the original lyrics here, either: