American spies were a major component in the Colonist win against the British. One well known American spy was Caleb Brewer. He was part of the Culper Spy ring and reported all his information back to George Washington.
The Battle of Trenton was fought on December 26, 1776 between the Continental Army and the Hessians. This battle was a result of the loss of the Battle of New York because the Continental Army needed a new base. While it was a small battle it was a still a valuable win for the Patriots.
The battle of Princeton occured 7 days after the battle at Trenton on January 2, 1776. The British came to defeat the already tired American Troops but Washington heard of their plan and snuck out. Now having the advantage the Continental Army beat the British resulting in the British leaving New Jersey to the Patriots.
The battle of Saratoga fought between September and October of 1717 in New York is known as the turning point in the Revolutionary War. British troops surrendered to the American troops resuling a in a crucial victory for the Patriots.
George Washington and his army camped out in Valley Forge for 6 months. Hunger and disease killed many of the army but slowly the army got stronger and stronger. 6 months later they came out of that camp with an army strong than ever.