According to Deborah Jenson’s research, this is the first publication of part of the Declaration of Independence in any American newspaper. See: Deborah Jenson, “Dessalines’s American Proclamations of the Haitian Independence,” Journal of Haitian Studies, (2009) 15(1): 89.
Haiti and the Atlantic World 
Hi Julia, would you also be interested in the first publication in a German newspaper?
Jeannette, yes! That would be wonderful! I will add you as an author so that you can write the post. Thank you!