Victoria here. I recently visited Fort McHenry in Baltimore, MD, where after a bombardment by the British Navy in 1814, American writer Francis Scott Key (1779–1843) wrote the words to the Star Spangled Banner, which became the American national anthem.
The Grand Union Flag was used from December 1775 to June 1777, incorporating the thirteen stripes for the 13 colonies and the British Union Jack.
Later there were several versions of the flag with thirteen red and white stripes and thirteen stars on a the latter either on a blue field in rows or in a circle.
There have been many, many U.S. flags over the years. Then I got to wondering where the Maryland State Flag came from, as it has a quite unique design. Turns out it is based on the heraldic arms of the founding family of the colony of Maryland, the Calverts, Barons Baltimore, incorporating the arms of the Crossland family as well. According to Wikipedia, it is the only state flag that is based on English heraldry.