Charles MacKubin Lefferts
Last Stand
Charles MacKubin Lefferts (1873–1923) was an American artist who specialized in historical paintings of the Revolutionary era. He is perhaps best known for his "Uniforms of the American, British, French, and German Armies in the War of the American Revolution.
From the uniforms and the fact that the attackers are on horseback, I surmise this to be a depiction of an encounter during the Mahdist War in the Sudan. Soon after, the British discontinued the red coats for khaki uniforms. The Sudanese conflict lasted from 1881-1899. Note the palm trees in the distance, center right.