British Red Ensign and American Independence
The British Red Ensign Flag was well-known in the American Colonies during the 1700s. The English Royal Navy adopted in in 1625, and it was used by English merchant ships from about 1650.
During the 1700s the British Red Ensign Flag was the official British flag, and since the American colonies were British, it was also their flag.
In 1776 George Washington and the Continental Army surrounded Boston. General Washington had the British Red Ensign Flag raised at Cambridge, but strips of white cloth were added to create red and white to make white stripes. This was before America declared itself independent in the following July. The point was that the colonists were still loyal to the king, while in open protest against the British Parliament’s abusive practices in the America.
The British Red Ensign Flag that was modified by the American Colonies became known as the Continental Colors, and later as the Grand Union Flag. It was in use for some time (the Stars and Stripes flag was not officially adopted until 1777).
Throughout the American Revolution, British soldiers fought under the British Red Ensign Flag. This is the flag British General Cornwallis was using when he surrendered in 1781.
Note: The red ensign is in informally called the “red duster”. There does not seem to be any agreement on how the expression arose. One theory is that Red Ensigns were hoisted and left until they were so dirty and tattered that they looked more like dusters than flags. Another is that on British ships old flags were often used as rags before being thrown away.