Complex sentence: Countee Cullen (May 30,1903--January 9,1946) was one of the leading American poets of his time and one of the lights of the Harlem Renaissance.
Split into simpler sentences: Countee Cullen (May 30,1903--January 9,1946) was an American poet. Cullen was one of the leading poets of his time and one of the lights of the Harlem Renaissance.