Judy's big plans for the summer seem ruined when two of her best friends go away, and then her parents leave her and Stink with Aunt Opal, but a new "thrill-a-delic" plan has her racing toward fun.

After learning about the American Revolution on a family trip to Boston, Judy Moody makes her own Declaration of Independence and tries to prove that she is responsible enough to have more freedoms, such as a larger allowance and her own bathroom.