The Tree Flag (or Appeal to Heaven Flag) was one of the flags used during the American Revolution. The flag, featuring a pine tree flag with the motto "An Appeal to God," or, more usually, "An Appeal to Heaven", was used originally by a squadron of six cruisers commissioned under George Washington's authority as commander in chief of the Continental Army in October 1775. It was also used by Massachusetts' state navy vessels in addition to privateers sailing from Massachusetts
The phrase is a particular expression of the right of revolution used by British philosopher John Locke's in Second Treatise on Civil Government which was published in 1690 as part of Two Treatises of Government refuting the theory of the divine right of kings.
Locke's works were well-known and frequently quoted by colonial leaders, being the most quoted authority on government in the 1760-1776 period prior to American independence. Thomas Jefferson was accused of plagiarizing Locke in certain sections of the Declaration of Independence by fellow Virginian delegate Richard Henry Lee.
Prior to Colonel Reed's suggestion and Massachusetts General Court establishing the Pine Tree flag as the standard of the Massachusetts navy, "an appeal to Heaven" or similar expressions had been invoked by the Massachusetts Provincial Congress in several resolutions, Patrick Henry in his Liberty or Death speech, and the Second Continental Congress in the Declaration of the Causes and Necessity of Taking Up Arms. Subsequently, it was used again by the Second Continental Congress in the Declaration of Independence.