This report focuses on the 55 largest public elementary and secondary school districts, measured by the number of students in membership, for the school year 1987-88. Information was analyzed from the 1987-88 school year Common Core of Data (CCD) series collected annually by the National Center for Education Statistics. The following summary findings are included: (1) the largest school districts are located in many parts of the country, but are mainly in the eastern third of the United States or in the sunbelt; (2) the 55 largest districts comprise less than 1 percent of all school districts but serve 17 percent of the total public elementary and secondary school population; (3) one district serves an entire state, some districts are coterminous with major cities, and other districts are located adjacent to major cities; (4) enrollments range from 939,900 to 57,100 students; (5) socioeconomic status, based on the percentage of students eligible for free lunch programs, ranges from 3 percent to 73 percent; (6) the racial/ethnic composition varies considerably, with three districts over 90 percent White, four districts predominantly Black, three districts predominantly Hispanic, and two districts in which Asian and Pacific Islanders are the norm. Statistical data are included on three graphs and nine tables. A list of the 500 largest public school districts in the United States and outlying areas for 1987-88 is appended. (FMW)