This is A New Map of England and France: The French Invasion, or John Bull Bombarding the Bum-Boats, a 1793 cartographic masterpiece that depicts an anthropomorphic Britain launching a tidal wave of feces across the English Channel at would-be French invaders and revolutionists.
This piece was drawn by English caricaturist James Gillray, who made his career on thousands of satirical cartoons. This map was Gillray's response to growing revolutionary zeal on the Continent. Explains the British Museum of this piece:
A comic map [...] is represented by the body of George III (John Bull), his head in profile to the right, wearing a fool's cap composed of 'Northumberland'. His left leg is drawn up, Norfolk forms the knee, the mouth of the 'River Thames' the ankle, Kent the foot. His outstretched right leg terminates as Cornwall. From the coast, at the junction of 'Hampshire' and 'Sussex', issues a blast of excrement inscribed 'British Declaration', which smites a swarm of 'Bum-Boats' extending from Ushant to the mouth of the Seine. The map is divided (inaccurately, and with omissions, but with a rough correctness) into counties, Wales representing the flying coat-tails of the King, who strides across the ocean with great vigour.
A 2000 exhibit from London's Tate Museum elaborates further on the meaning of George III's scatological declaration:
The ‘British Declaration' emitting from John Bull's backside refers to a royal promise that the port of Toulon, then occupied by the British, would be ceded to France on the restitution of its monarchy.
BONUS #1: The United States of Pork, circa 1876.
BONUS #2: Fart scrolls, always fart scrolls.
[Spotted on Retronaut]