During the period between World Wars I and II, two major historical developments powerfully influenced the course of economic ideas for the remainder of the twentieth century. The first was the Bolshevik Revolution of 1917 (and the ensuing civil war) and the unprecedentedly rapid industrialization of the Soviet Union over the next several decades. The pace of industrialization in the Soviet Union was particularly impressive because it occurred despite the impediments of what was tantamount to a second civil war in the 1930s in addition to the staggering devastation inflicted on the Soviet Union by Germany in World War II. The second major event that had a significant impact on subsequent economic theory was the Great Depression of the 1930s. In this chapter, we will briefly examine each of these historical developments and then, in this and the final two chapters, we will show the impact they had on subsequent economic theorizing.