This booklet offers a census of course offerings and enrollments in social studies in junior and senior high schools in Illinois. It is part of a series of reports surveying statewide basic curriculum data. Data were collected in 1977 from 459 public junior high schools and 704 public high schools. The document is intended for use by school administrators, school board members, teachers, parents, legislators, and others who have a role in making decisions about public education in Illinois. Specifically, the data can help educational policy makers by providing background data on issues including modifying programs in light of declining enrollments, reallocating resources, and assessing the impact of federal regulations and state laws mandating equal access to all school programs for boys and girls. In addition to information on course offerings, information is presented on school size and community type (central city, suburb, independent city, or rural). Highlights of the report are that every Illinois secondary school offers social studies courses; United States history is required of all students for graduation from eighth grade and high school; there is no direct relationship between the frequency with which a course is offered at the high school level and the level of enrollment; over 50% of the high school social studies courses are electives; there are no sex differences in enrollment in social studies courses; enrollment declines may induce schools to reduce the number of social studies courses; and competency testing in the social studies is becoming increasingly broadened. (Author/DB)