Using data collected in the 1999-2000 Schools and Staffing Survey (SASS), this report studies the characteristics of schools serving immigrant children at the time of NCLB's passage. As SASS lacks a measure of immigration status among school children, this analysis uses English language proficiency level (or LEP status) as a proxy for immigrant status, recognizing that some LEP students may be neither immigrants nor their first-generation children, but rather second- or third-generation U.S.-born children. Focusing on nationally-representative information about elementary schools, principals, and teachers, the study compares differences between schools with high proportions of LEP students and schools with fewer and no such students to examine potential differences among the schools educating the nation's young. The following are appended: (1) List of Figures and Tables; and (2) Statistical Tables. (Contains 5 figures, 10 tables, and 20 footnotes.) [This report is part of the Program for Evaluation and Equity Research (PEER).]