This depends on two things. First of all, do you really mean the 19th century or do you mean the 18th century? Second, if you mean the 18th century, do you mean the end of the century as in the late 1790s or are you talking about a time nearer to when the Declaration was issued?
The farther you get from the actual issuance of the Declaration, the less importance it has in the relationship between the British and the Americans. That is because many other factors intervene. For example, by the end of the 1790s, the fact that the US declared independence was much less relevant than the fact that they won independence (and the fact that the French Revolution had happened).
Therefore, I do not think that you would want to look at the impact of the Declaration of Independence, as opposed to the impact of actual American independence.
i am sorry, i made mistakes. i wanted to say 1790s.
i would like to shed more light on the circumstances in which it was wrtiien and the impact of it on the usa and britain. i am a student from africa, and i have to produce a research paper.
i want to do something about american civilization. could this topic be interesting, or could you suggest another topic for me please?