[1] From 1967 to 1971 he taught at Johns Hopkins University, where he served as director of the Institute of Southern History.
While teaching at the University of Maryland, he began a new line of scholarship involving the making and implementation of federal policy.
These studies led to three major books and a national reputation as the most successful pioneer in the new field of policy history.
[2] His first policy study, The Uncertain Triumph (1984), dealt with the enactment and implementation of major federal aid for public education.
It showed how early civil rights legislation, intended largely to correct injustices to African Americans, eventually offered protections to immigrant minorities who were among Americans with the highest incomes, revealing "the often unforeseen, or unwanted, effects of social legislation".