Addendum, consists almost exclusively of letters sent and received by De Leon concerning specific ideological and party procedure disputes with the Socialist Labor Party in the form of typewritten and handwritten correspondence as well as letters clipped from the letters to the editor column of The Daily People and Weekly People. Correspondents include such party notables as Daniel De Leon and Arnold Petersen. Also included is a political allegory of the class struggle written by Solon De Leon and entitled "Step At A Time And Something Now."
