New York: New York Labor News, 1935. 12mo. Wraps. 39 p. + appendix. 
A partisan, political portrait of the man who is sometimes known as "Zig-Zag" Foster because of his agility in navigating abrupt changes in the Party line, written by the leader of the Socialist Labor Party. Petersen's typically subtle and nuanced analysis concludes: "Bluff and bluster, fakes and frauds, Anarchist egotism and yellow cringing and ducking of the renegade, with overwhelming indications of agent provocateurism, these are the high spots in the zig-zag career of William Zebulon Foster - S. P. reformer, Anarcho-Syndicalist, war monger, patriot, ally and friend of Sammy Gompers, Anarcho-Communist, advocate of bonus for reactionary legionnaires, and friend and admirer of the bitterest foes of Soviet Russia, whose leading men, with an obtuseness that passeth all understanding, extend to him recognition as the official American representative of the workers' first Proletarian Republic!"