Complex sentence: Roger Nash Baldwin, founder of the American Civil Liberties Union (ACLU), leftist, anarchist, and Communist, was born in Wellesley, Massachusetts to comfortably situated parents, in 1884.
Split into simpler sentences: Roger Nash Baldwin (21 January 1884--26 August 1981) was one of the founders of the American Civil Liberties Union (ACLU). Baldwin was born in Wellesley, Massachusetts to comfortably situated parents, in 1884.