American's were familiar with many different flags around the time of the Revolutionary War. These are the more famous ones:
The Rattlesnake Flag-the snake symbol first came to be when it was used as a plea for uniting colonies in the French and Indian War when Ben Franklin made a cartoon using it. It came back when America was preparing to unite against another common enemy-Britain. It is also commonly referred to as the Gadsden flag.
The Liberty Tree Flag- became a symbol for the colonists after it was cut down by the British. The liberty tree was in Boston, and received its name because meetings were held under the tree in 1765 by the Sons of Liberty association. There were other flags designed with the liberty tree on it, however this is the most widely recognized one today.
The Grand Union Flag- many colonists considered themselves loyal subjects of Britain, so this flag greatly resembled Britain's. The British Union in the top left corner was removed and replaced with the white stars after the final breach of Britain's trust in the colonies.