Paul Le Blanc is an American historian at La Roche University in Pittsburgh as well as labor and socialist activist who has written or edited more than 30 books on topics such as Leon Trotsky and Rosa Luxemburg.
A comprehensive collection of primary source documents on the period of U.S Trotskyism from its founding to 1940, compiled by obvious partisans of the man. Very useful, if you're into that sort of thing.