Regional and State inequalities in educational opportunity are reported from an extensive study based on data from the October 1965 Current Population Survey of the U.S. Bureau of the Census regarding the home and school environments of approximately 27,000 persons between the ages of six and 19 in a national sample of households. Major phases of the report include (1) the role of the public school in the equalization of educational opportunity; (2) modernization and education within American society; (3) an open-systems approach to social organization; (4) the American public school as an open social system; (5) regional, metropolitanizational and social class variations in American society; (6) theoretical considerations; (7) background of the school context study; and (8) modernization context as related to the organizational structure, organizational inputs, and the production throughput and output of American public schools. The study concludes that efforts to attain equality of educational opportunity in the schools can be achieved only to the extent that educational inputs, outputs, and functions are determined by policies and practices which perceive this end as a significant part of the school's institutional role. (JK)