[1] After graduating from Radcliffe, Cromwell taught sociology at Hunter College, where she was the first African-American instructor.

[10] In 1960, Cromwell traveled to Ghana to convene the first conference of West African social workers.

[1] Cromwell has served on the executive council of the American Society of African Culture, the now-defunct American Negro Leadership Conference in Africa, and the United States Agency for International Development's Advisory Committee on Voluntary Foreign Aid (ACVFA).

[1] She is president of the Heritage Guild, which she co-founded in 1975 to document, preserve, and raise awareness of Boston's black history.

At that time, few Bostonians realized the historical significance of sites such as the African Meeting House on Beacon Hill, or knew that Boston's West End had once been a major center of the abolitionist movement.

The Heritage Guild has called the public's attention to historical sites and the achievements of people such as Butler R. Wilson, founder of the Boston NAACP.