By Tom Cohen, CNN
Washington (CNN) - When Derrick Bell was a young lawyer in the Department of Justice's new Civil Rights Division in the late 1950s, his supervisor told him to drop his membership in the National Association for the Advancement of Colored People.
Bell refused, and soon saw his caseload reduced and desk moved into the hallway. Eventually he resigned.
It would not be the last time Bell gave up a prized position for a principle. Years later, he left Harvard Law School - where he had been the first tenured African-American professor - over the lack of any black women on the faculty.
Bell was a legal scholar who broke racial barriers in a career that influenced students, including a young Barack Obama at Harvard. He died last October.