There were three epochs of growth experience after the mid-nineteenth century for what is now called the OECD “club”: the late nineteenth century, the middle years between 1914 and 1950, and the late twentieth century. The first and last epochs were ones of overall fast growth, globalization, and convergence. The middle years were ones of overall slow growth, deglobalization, and divergence. Thus history offers an unambiguous positive correlation between globalization and convergence. When the pre-World War I years are examined in detail, the correlation turns out to be causal: globalization played the critical role in contributing to convergence.