BOSTON (AP) — William Strickland, a longtime civil rights activist and supporter of the Black Power movement who worked with Malcom X and other prominent leaders in the 1960s, has died. He was 87.

Strickland, whose death April 10 was confirmed by a relative, first became active in civil rights as a high schooler in Massachusetts. He later became inspired by the writings of Richard Wright and James Baldwin while an undergraduate at Harvard University, according to Peter Blackmer, a former student who is now an assistant professor of Africology and African American Studies at Eastern Michigan University.

“He made incredible contributions to the Black freedom movement that haven’t really been appreciated,” Blackmer said. “His contention was that civil rights wasn’t a sufficient framework for challenging the systems that were behind the oppression of Black communities throughout the diaspora.”