Selectively, of course. Britain's position on our Declaration of Independence:
The Declaration of Independence was not only illegal, but actually treasonable. There is no legal principle then or now to allow a group of citizens to establish their own laws because they want to. What if Texas decided today it wanted to secede from the Union?
*Lincoln made the case against secession and he was right. The Declaration of Independence itself, in the absence of any recognised legal basis, had to appeal to "natural law", an undefined concept, and to "self-evident truths", that is to say truths for which no evidence could be provided.
But in defense of America's first secession:
For American lawyers, the answer is simple: "The English had used their own Declaration of Rights to depose James II and these acts were deemed completely lawful and justified," they say in their summary.
And, of course, Southern secessionists used America's secession from Britain to support their position, as did some Northern newspapers:
If [the Declaration of Independence] justifies the secession from the British empire of 3,000,000 of colonists in 1776, we do not see why it would not justify the secession of 5,000,000 of Southrons from the Federal Union in 1861. – New York Tribune, 17 December 1860
Precedent is a powerful and weighty argument. Of course, the legality of secession is one discussion, the wisdom and prudence of it is quite another. Read the complete story here.
*However, following Lincoln's logic he was, himself, illegitimate and should have surrendered the whole nation back to Great Britain - right?