Complex sentence: The minstrel show, or minstrelsy, was an American form of entertainment developed in the 19th century of comic skits, variety acts, dancing, and music, performed by white people in blackface or, especially after the U.S. Civil War, by black people.
Split into simpler sentences: The minstrel show, or minstrelsy, was an American form of entertainment developed in the 19th century. Each show consisted of comic skits, variety acts, dancing, and music, performed by white people in make-up or blackface for the purpose of playing the role of black people.