1776 was a really great year, starting out with the people of New Hampshire declaring its independence from the British Crown and its oppressive government. A government denying its people their rights under common law and the Magna Carta denying the representation in governing. Not all of the British subjects in the colonies were so brave and clear minded as to realize that loosing their lives physically would be better than living them as slaves to the crown. It has been pointed out that for some it was a terrible year, but then that is speech come 230+years late. To say that, however we may read the history, is to say the idea that freedom from an oppressive ruler was a sad and lousy turn of events. To guess the mind of Washington! Thinking that it was the British which chased him and not he leading them to where he wanted them. To imagine only one Benedict Arnold, or that all of his officers gleefully submitted to Washington isn't a good read of history. To suggest that troops deserted "taking their weapons with them" as if they were expected to leave them, further shows a lack of understanding of the reality.
Washington managed to concentrate the majority of the British forces to the NY/NJ area and convinced Gen. Howe he "destroyed the continental army". Howe sent a lesser General Cornwallis, who was on Christmas holiday, to "chase" Washington after the "guns for hire" Hessians were defeated. As a later general said, "War is Hell", he might have added, "and it knows no holiday". Washington was not a narrow minded, clueless individual who gave orders and stood back; he learned and listened, kept his own consul, he knew that men fighting for their freedom were to be led and he stood with them.
As far as Washington's Army being ill-clothed and sick, it was the continental government that didn't hold up to its promises, (nothing has really changed since).
Be thankful we still can celebrate the birth of "our" nation; and say a prayer for those billions in the world who don't have such freedoms and a prayer for those in this nation who can only find the negative and want the rest of us to accept it as truth.