The origins of "Political Correctness” or "Cultural Marxism" can be found in the early parts of the 20th century from the Frankfurt School, which was the headquarters for the Communists scheming in Germany. Max Horkheimer, T.W. Adorno, Herbert Marcuse, Leo Lowenthal, and Erich Fromm were all there.
"The role of the Frankfurt School is creating the victim groups that constitute the politically correct coalition."
This short documentary was made by the Free Congress Foundation and narrated by William S. Lind.