Why did the declaration of independence increase americans motovation to fight and win the war

When the Declaration of Independence was written, the war had already been going on for a year or so. At the start of the war, all the colonists were fighting for was a more equitable place for themselves as a member of the British Empire, with voting rights in Parliament, a voice by which they could express their discontent about taxes and such. In other words, when the war started there was no talk about establishing independence for themselves, that whole concept didnt come about till later, with the Declaration. So once it was established that this was a war for their independence from Britain, that brought a whole new light on things, now they were fighting to become their own country, quite different that just asking for more say so over their affairs.

The war was raging and when they made the document, everyone was like huh, we are our own country and we will do whatever it takes to keep it that way! Then they went out and whupped the British.