Question

What main purpose of the declaration of independence was to

Answer 1

the purpose of it was to declare independence from the kings rule. 

Answer 2

The main purpose of the Declaration of Independence was to declare the separation of the colonies from Britain.
The colonies were created by Britain, but given that they were so far from their mother country, they wanted their independence to rule their colonies based on their own laws. This is why the Declaration was created - to announce that the colonies would no longer depend on Britain.