In March 1976, there were 11.1 million persons of Spanish origin in the United States. These included 6.6 million persons of Mexican origin, 1.8 million of Puerto Rican origin, about 700,000 of Cuban origin, and about 2.1 million of Central or South American and other Spanish origin. This report provides a statistical description of the social, economic, and demographic characteristics of the Spanish origin population in the United States. The information is compiled from data collected in the March 1976 Current Population Survey. Information is given on the total U.S. population, and the Spanish origin population and its subcategories (Mexican, Puerto Rican, Cuban, Central or South American, and other Spanish origin). Supplemented by text tables and graphs, the report includes information on size, composition, age, sex, marital and family status, education, employment, occupation, income, and other characteristics of these populations. The source and reliability of the estimates are discussed. (NQ)