German sociologist Alfred Vierkandt is hardly remembered today. This may seem surprising. Several prominent sociologists from the German-speaking countries contributed to the Handwörterbuch der Soziologie (1931), which Vierkandt edited and published. However, Vierkandt did not interact with any of them significantly, and this publication brought no recognition of the importance of his sociological oeuvre in Germany, the United States, or elsewhere. His key notion of the social group found no acknowledgment among other contemporary or later sociologists, even though several of them used this notion and discussed social groups in their own writings. Moreover, those who paid close attention to his writings, like Abel and Hochstim, evaluated them quite critically. Both before and after World War II, Vierkandt remained a solitary and relatively unknown author.