Adelaide McGuinn Cromwell died peacefully in hospice care on June 8. She was 99.

A professor emerita of sociology at Boston University, she held her final class in Brookline, where she had lived for 44 years. She had long encouraged her acolytes — here, near and abroad — to improve themselves as global citizens, with a particular imperative to empower women, especially those of color, and cherish the vulnerable, the promising and the brave.

She had also owned a home in Vineyard Haven for decades and loved spending time on the Island. “You can live the kind of life you want to live here. There is a certain freedom,” she told the Gazette in a 2008 interview.

An influential Afro-American intellectual, feminist scholar, nurturing teacher, academic administrator, and persistent agent of benevolent disruption, Dr. Cromwell was a native of the District of Columbia where her family was distinguished for its accomplishments in law, journalism, accounting, scholarship and education. She was a Phi Beta Kappa graduate of Smith College’s Class of 1940 (four decades after her aunt Otelia had become the school’s first black alumna) before earning graduate degrees from the University of Pennsylvania, Bryn Mawr, and ultimately a doctorate from Radcliffe in 1953.

By then she had already become the first black to teach at Hunter College as well as at Smith. Hired by Boston University, she became one of the founders of its African Studies Program, the second in its field in the country. In 1969, she initiated the university’s Afro-American Studies program as one of the first in the nation to specialize in post-graduate degrees. An author of several studies of the roles of elites in different contexts, she is best known for her book The Other Brahmins: Boston’s Black Upper Class 1750-1950.

Dr. Cromwell is survived by her son, Anthony Cromwell Hill of Cambridge and Vineyard Haven.

A memorial service will be held on Nov. 5 at 1 p.m. in Boston University’s Marsh Chapel.