Samuel B. Griffith II.
The War for American Independence: From 1760 to the Surrender at Yorktown in 1781.
Urbana & Chicago, University of Illinois Press, 2002.
(Orignially published as: In Defense of the Public Liberty, Garden City, N.J.: Doubleday, 1976.)

Griffith's book is an excellent supplement to the more frequently read book:

Robert Middlekauff.
The Glorious Cause: The American Revolution, 1763-1789
New York & Oxford, Oxford University Press, 1982.
(Series: The Oxford History of the United States)

Griffith uses more direct quotes from primary sources than Middlekauff to tell the story of the War and of the evolution of American Independence from Britain. As I mentioned before, Griffith's book has a more through treatment of the military, diplomatic and political (especially in Britain) sides of the War than Middlekauff's.
However, Griffith's book ends with the formal surrendur of Cornwallis on 19 October 1781 at Yorktown, Virginia. The war continued until at least a preliminary peace treaty of 20 January 1783, and the final peace treaty was signed on 3 September 1783. How did the war wind down militarially? This isn't covered by either Middlekauff or Griffith. What about the diplomatic details from approximately 1780 through the final peace of 1783? You'll have to look elsewhere for that too (Middlekauff refers us to: Samuel Flagg Bemis, The Diplomacy of the American Revolution, 1935; reprint ed., Bloomington, Indiana, 1957; and Richard B. Morris, The Peacemakers: The Great Powers and American Independence, New York, 1965). (This is probably a complicated and interesting bit of history since it involved several treaties amongst the United States, Britain, France, and Spain.) My hazy memory of events treated in Middlekauff's book through it's end now leads me to re-read the final 100 pages of his book. From my initial reading of Middlekauff I came away wanting to know more about the development of the Constitution of 1787. To make up for this, I am also Currently Reading:

George McClellan.
Liberty, Order, and Justice: An Introduction to the Constitutional Principles of American Government, Third Edition (called "Revised Second Edition" on the publisher's web page).
Indianapolis: Liberty Fund, 2000.

I find this an outstanding text on the American constitutionalism. Each narrative / analytical / interpretative chapter is followed by many source documents, from the Magna Charta (1215), to three Federalist papers (1787-8), through the most recent Ammendment (the 27th of 1992) to the Constitution of 1787. This book fills a huge gap in my education (and I doubt that few would not benefit from reading this book).