Although It Didn't Happen Here addresses a rather familiar question—Why is there no socialism in the United States?—this is an exciting book. Its central chapters discuss the major explanations for American “exceptionalism” that have been proposed over the past century—namely, the distinctive character of U.S. political institutions, the ethnic heterogeneity of the nation's population, the divisions between labor unions and the socialist party, the sectarianism of American socialists, the repression that radicals encountered, etc. Political scientists will find the topics of many of these chapters familiar too.