Are U.S. Prep Schools Still Excluding Working-Class Black Students?

In the 1980s, the percentage of Black students attending the U.S. power elite's prep schools whose family background was low-income and working-class apparently decreased. As G. William Domhoff and Richard Zweigenhaft's noted in their 1991 book Blacks in the White Establishment: A Study of Race and Class in America:

"The ABC [`A Better Chance'] program was founded in 1963 by 16 independent secondary schools, with assistance from Dartmouth College, the Merrill Foundation, and the Rockefeller Foundation...The changing role of ABC, and the increasing entry of middle-class blacks into private schools are reflected in the one survey we know of that provides a comprehensive look at the racial composition of elite prep schools in the 1980s. It indicates that the number of black students has leveled off and that more of them are from the middle class. In their study of 2,475 freshmen and senior students at twenty prep schools, Peter Cookson and Caroline Persell found that 106 were black (4 percent). Notably, the fathers of 70 percent of their black sample were professionals: 17 percent were doctors, 14 percent were lawyers, 6 percent were bankers, 8 percent were college teachers, and 25 percent were secondary school teachers. One-third of the black respondents indicated that their families earned more than $75,000 per year [equal to over $153,000 in 2018]..."