In 1968, he accepted a teaching position at the University of Southern California. But he was recruited by Harvard Law School, where students were pressuring the administration to hire a black professor. Mr. Bell conceded that he did not have the usual qualifications for a Harvard professorship, such as a federal court clerkship or a degree from a top law school. In 1980, Mr. Bell became the dean of the University of Oregon School of Law, but he resigned in 1985 when an Asian woman was denied tenure. After returning to Harvard in 1986, he staged a five-day sit-in in his office to protest the school’s failure to grant tenure to two professors whose work involved critical race theory. In 1990, he vowed to take an unpaid leave of absence until the school, which had never had a black woman on its tenured faculty, hired one. Two years later, the school refused to extend his leave, effectively ending his employment. By then, Mr. Bell was teaching at New York University Law School, where he remained a visiting professor until his death. Harvard Law School hired Ms. Guinier in 1998. “Most people think of iconoclasts as lone rangers,” Ms. Guinier said. “But Derrick was both an iconoclast and a community builder. When he was opening up this path, it was not just for him. It was for all those who he knew would follow into the legal academy.