Us Declaration of Independence. legal?

July 4ht, Americas founding fathers signed a document that announced their sovereign nation ‘ The Declaration of Independence.’

An event, Temple American Inn of Court, turned British lawyers against American to find out if the declaration was legal.

A vote at the end of the meeting decided that they wouldn’t decide anything now but they would wait.

‘The legality of the declaration is proven by subsequent independence movements, which have been formed by world opinion. However the Brits disagree. They believe that was illegal.  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.
The grievances listed in the Declaration were too trivial to justify secession. The main one - no taxation without representation - was no more than a wish on the part of the colonists, to avoid paying for the expense of protecting them against the French during seven years of arduous war and conflict.’ This is a quote from the BBC news page.