British Union Jack

This flag design was created by King James VI of Scotland when he became King of England in 1603. It was created by combining England's red cross of ST. George with Scotland's white cross of ST. Andrew. This was the flag that flew above all the early English settlements in the new world. It was the most commonly used flag in the English colonies until the beginning of the Revolutionary War in 1775.

Source: http://www.anyflag.com/history/britunio.htm