This flag was used by George Washington on his squadron of six schooners which he outfitted at his own expense in the fall of 1775. This flag was a variation of the New England Pine Tree flag. The Sons of Liberty would rally under a large tree, in Boston Massachusetts, which came to be known as "The Liberty Tree". This tree became a symbol of American independence. Knowing they were up against a great military power, they believed they were sustained by still a greater power, thus their "APPEAL TO HEAVEN". You've probably all heard the quote regarding the tree of Liberty. The Son's of Liberty is where that comes from and this would be the tree.