I am writing an APUSH DBQ and I have what I think is a pretty winning thesis but I am having problems coming up with a good, interesting opening sentence. I figure once I have the first paragraph figured out the rest will flow rather easily. I also need to figure out a sentence for after my thesis, something my teacher calls a "Plan of Attack" where you basically list what your paragraphs will be about.

Question

Here is the DBQ: To what extent had the colonists developed a sense of their identity and unity as Americans by the eve of the Revolution?
The thesis I wrote it this: By the time the American Revolution began, colonists of North America had developed such a sense of unity and identity that they were prepared to separate themselves from Britain and create a new, free nation even if that meant giving up everything they had.
I wrote it this way to a)include a time frame b)incorporate both Unity and Identity, the two main themes and c)to set myself up with a basic theme to base the rest of the essay on. I want to have my essay layout have the body paragraphs be 1. How the British had caused them to become united, 2. How becoming united had led to them forming an identity and what that identity was, 3. How these two things were to such an extent that the colonists were prepared to begin the revolution.
I just need help finishing my introduction paragraph and I would also like to know if this structure creates a good DBQ essay?