In recent years social scientists have become newly interested in the Spanish-speaking population of the United States. The 1960 U.S. Census of Population gives a figure of over 3.5 million persons of Spanish surname concentrated in the five southwestern states of Texas, New Mexico, Colorado, Arizona, and California alone. It has been estimated that the 1970 census will show from 9 to 10 million in the entire U.S.1 Even though California has the largest number of persons with Spanish surnames, followed closely by Texas, the percentage of such persons in relation to the total state population is highest in New Mexico (28.3%). However, although the percentage of Americans of Spanish heritage in the other states mentioned increased during the decade 1950-1960, it declined in New Mexico. In fact, this percentage has been gradually declining in New Mexico ever since its conquest by the United States in 1846. As late as 1940, over half the population of this state was of Spanish descent.
These figures suggest that the social facts in regard to the Spanish-American population of New Mexico may be somewhat different from other areas in the United States with large-sized Spanish-surname populations. A closer look at the state confirms this impression, as will be shown in the succeeding chapters. Certainly in order to understand these facts, the history of the