The modern concept of the wealth of nations emerged by the early twentieth century. Capital embodied in people human capital mattered. The United States led all nations in mass postelementary education during the human-capital century.' The American system of education was shaped by New World...

Human capital accumulation and technological change were to the twentieth century what physical capital accumulation was to the nineteenth century -- the engine of growth. The accumulation of human capital accounts for almost 60% of all capital formation and 28% of the per capita growth residual...

A new state-level series on secondary-school data demonstrates that graduation and enrollment rates increased greatly in the 1920s and 1930s in most regions. An 18-year old male in 1910 had just a 10% chance of having a high school diploma but by the mid-1930s the median 18-year old male was a...