SONG OF LIBERTY

In Peter Ackroyd's book, Blake: A Biography, he writes of the political situation which existed in Britain during the productive years that Blake lived at Lambeth.
 
"Habeas Corpus had been suspended in the spring of 1794 but now two acts were passed against 'treasonable and seditious Practices' as well as 'Seditious Meetings and Assemblies'. These laws, flawed and uncertain though they were in execution, effectively marked the end of organized radicalism in London. In the spring of 1797 Blake dined with his publisher, Joseph Johnson, in the company of Fuseli among others; in the following year Johnson was arrested for selling a seditious pamphlet attacking an anti-radical track entitled An Apology for the Bible, and was sentenced to six month's imprisonment in the King's Bench Prison near Blake's house in Lambeth. In the same year Blake furiously annotated a similar tract but added, at the beginning, "To defend the in this year 1797 would cost a man his life. The Beast and the Whore rule without controls...I have been commanded from Hell not to print this as it is what our enemies wish'. It was not printed but, more to the point, there is no evidence that he ever again attached himself to any formal or informal political cause." (Page 181)
 

Wikipedia commons Book of Urizen
Plate 20, Copy A

Although Blake was drawn into the political world of his day with the threats, limitations and turmoil of a revolutionary age, his attention was focused on the inner man. His desire was always that the individual achieve the liberty of knowing he belonged to God's family.

There was no further need for Blake to write a radical political document since in 1792 he had engraved his Song of Liberty which he appended to Marriage of Heaven & Hell. His whole idea of revolution as a prelude to rebirth is expressed in this song. Orc the new born terror confronts the starry king, who as an image embodies Urizen, King George and Moses. The world is reborn as holy without the need of empires, priests or laws. The release of the eternal horses signals the return to Eden.
  
Marriage of Heaven & Hell, Plate 25, (E 44)
 " A Song of Liberty

1.  The Eternal Female groand! it was heard over all the Earth:
2.  Albions coast is sick silent; the American meadows faint!
3  Shadows of Prophecy shiver along by the lakes and the rivers
and mutter across the ocean! France rend down thy dungeon;  
4.  Golden Spain burst the barriers of old Rome;
5.  Cast thy keys O Rome into the deep down falling, even to
eternity down falling, 
6.  And weep!                                
7.  In her trembling hands she took the new, born terror howling;
8.  On those infinite mountains of light now barr'd out by the
atlantic sea, the new born fire stood before the starry king! 
9.  Flag'd with grey brow'd snows and thunderous visages the
jealous wings wav'd over the deep.
10. The speary hand burned aloft, unbuckled was the shield,
forth went the hand of jealousy among the flaming hair, and 
[PL 26] hurl'd the new born wonder thro' the starry night.
11. The fire, the fire, is falling!
12. Look up! look up! O citizen of London. enlarge thy
countenance; O Jew, leave counting gold! return to thy oil and
wine; O African! black African! (go. winged thought widen his
forehead.) 
13. The fiery limbs, the flaming hair, shot like the sinking sun
into the western sea.
14. Wak'd from his eternal sleep, the hoary, element roaring
fled away:
15. Down rushd beating his wings in vain the jealous king: his
grey brow'd councellors, thunderous warriors, curl'd veterans,
among helms, and shields, and chariots horses, elephants:
banners, castles, slings and rocks,
16. Falling, rushing, ruining! buried in the ruins, on Urthona's
dens.
17. All night beneath the ruins, then their sullen flames faded
emerge round the gloomy king,
18. With thunder and fire: leading his starry hosts thro' the
waste wilderness [PL 27] he promulgates his ten commands,
glancing his beamy eyelids over the deep in dark dismay,
19. Where the son of fire in his eastern cloud, while the
morning plumes her golden breast,
20. Spurning the clouds written with curses, stamps the stony
law to dust, loosing the eternal horses from the dens of night,
crying

  Empire is no more! and now the lion & wolf shall cease.

          Chorus

  Let the Priests of the Raven of dawn, no longer in deadly
black, with hoarse note curse the sons of joy.  Nor his accepted
brethren whom, tyrant, he calls free; lay the bound or build the
roof.  Nor pale religious letchery call that virginity, that
wishes but acts not!
  For every thing that lives is Holy"