The article examines the issues of determining the place of O. Holmes' work in the history of legal thought in general and the United States in particular, which remains, according to leading domestic and foreign experts, one of the difficult and cross-cutting problems in highlighting the evolution of the legal-realistic direction. At the same time, significant inaccuracies remain in explaining what constitutes and what includes the so-called legal realism in the United States. A more precise explanation of the problems of this phenomenon in intellectual culture from the end of the XIX century to the present has not only scientific and cognitive significance, but also socio-cultural, as it answers a very significant question about possible directions and trends in the development of modern fundamental jurisprudence. In addition, the question of the specific philosophical and methodological foundations of O. Holmes' legal views remains relevant. The scientific novelty of the research lies primarily in a more precise explanation of the nature and orientation of legal realism in the United States, the role of O. Holmes' views in the formation of this trend in American legal thought. It is shown that this direction is heterogeneous and is only a refraction of specific larger trends in the legal science of the XIX century, as well as the important fact that the influence of pragmatism was not of significant importance, since it is through the unification of this philosophical and psychological direction with the ideas of later realists that legal realism in the USA is transformed into its modern version.