The key factor to the de facto inequality typically maintained in America's city school system is found to be the teacher assignment system. Data from 69 cities are examined to determine whether this meant a systematic tendency to assign Black teachers to Black students. Poor and non-white students are kept at least partially segregated, and the more experiences and more verbally able white teachers are assigned to schools attended by the less disadvantaged white children. There is a strong regional dimension to this inequality and discrimination found existing in the school systems. Effective discrimination rises more or less continously as the South is approached, reaching a maximum level of complete segregation of students, with all Black students taught by Black teachers, and all white students taught by white teachers. Outside of the South, there is also some evidence that racial integration in the schools is reduced as the percentage of Black students, and especially of Black teachers, increases. Black students are then more likely to be segregated, and less likely to be assigned to white teachers. The relationship of effective pupil discrimination to pupil segregation and to a discriminatory teacher assignment is analyzed in a technical appendix. (RJ)