Jean-Jacques Dessalines to James Walker and Hugh Cathcart, 28 and 29 August 1803, MS 72, National Library of Jamaica.

Also three copies available at The National Archives of the UK:

Jean-Jacques Dessalines to James Walker and Hugh Cathcart, 28 and 29 August 1803, CO 137/110, The National Archives of the United Kingdom.

AND

Two copies in the following folder:

Jean-Jacques Dessalines to James Walker [and Hugh Cathcart], 28 and 29 August 1803, ADM 1/253, The National Archives of the United Kingdom. [I am missing a page from this version]

AND