The Norman Leonard Collection holds documents of the Subversive Activities Control Board (SACB) hearing in 1955-1956 on the California Labor School (CLS) when that law firm represented the School. The Collection includes transcripts for each day of the hearing and approximate 260 exhibits which the SACB introduced into evidence.

Forty-five exhibits were copies of the People's World and other documents by or about the Communist Party. The balance consisted of CLS documents - term catalogs, flyers, class outlines, etc. - which will provide researchers additional documents and supplement the Archives CLS Collection. Of significance are documents describing the founding and activities of the Southern California Labor School (Southern CLS), as there is no material on that branch in the original CLS Collection.