This article examines the data contained in the last volume of our five-part index of 16th Century Spanish emigrants to the New World. Originally entitled the Indice geobiográfico de 40, 000 pobladores españoles de América en el siglo XVI, the series in fact now furnishes biographical data on a total of roughly 55,000 individual men, women, and children, known to have emigrated to the Indies before 1600, whose birthplace we have identified from contemporary records. So far we have found publishers only for the first two of these five useful reference volumes, however a series of articles in both Spanish and English have presented our findings on each of the roughly twenty-year periods into which we have divided that all-important century during which Spanish colonial society was first taking shape. Though in conducting this basic research our primary goal has always been a linguistic one, i.e., to shed light on the early dialect differentiation of New World Spanish, the work is designed to be of use to historians and sociologists also.