It is a well-known fact that the writings of John C. Calhoun were read and admired by German political theorists in the latter part of the nineteenth century. When the problems of federalism became predominant in the German Empire, it was found natural to turn to American experience and to study the works of the leaders of contending factions in the United States before the Civil War.There may, however, be another reason why Calhoun, in particular, proved such a valuable source for the German authors. His theory of the concurrent majority, in many parts, presents a striking resemblance to the arguments advanced on the continent of Europe in defense of legislatures built on representation, not of individuals, but of groups, interests, or estates. It can be assumed that Calhoun, when speaking of the safeguards necessary against the despotism of the numerical majority, was thinking primarily of the federal system and states' rights. On the other hand, he can hardly have regarded this arrangement as the only possible solution to his problem. He defines the government of the concurrent majority as one “where the organism is perfect, excludes the possibility of oppression, by giving to each interest, or portion, or order,—where there are established classes,—the means of protecting itself, by its negative, against all measures calculated to advance the peculiar interests of others at its expense.” Especially in view of the expression “where there are established classes,” it seems safe to say that Calhoun probably knew of the existence of representation by estates of the realm in European countries, and regarded such systems with favor.