The "Flag of the United Colonies" displayed in 1775 featured three horizontal stripes

https://andregoty037.cavandoragh.org/pirate-flags-at-home-expressing-freedom-and-identity-the-bold-way

The "Flag of the United Colonies" displayed in 1775 featured three horizontal stripes and was flown by patriots in the hunt for greater autonomy from British governance earlier than complete independence.