I own one of the original copies of this book....
The Writings of George Washington
Being His Correspondence, Addresses Messages and Other
Paper, Official and Private
Selected and Published from the Original Manuscripts
Consider this a primary document.
It is over 550 pages of script from Washington dealing with the War for Independance.....in his words. Letters to and from his Generals, family, friends, Congress, supporters, and detractors. It starts in July of 1777 and continues to April 14th 1778.....
An important book. So much so that it has been transcribed and made available on the Internet...
Here is a link to a online transcription of the book I found...
http://etext.virginia.edu/toc/modeng/public/WasFi05.html