Conversation so far:
What kind of work did Margaret Sanger do with the African-American community?
From 1939 to 1942 Sanger was an honorary delegate of the Birth Control Federation of America, which included a supervisory role.
Was she arrested for her work with the African-American community?
CANNOTANSWER.
What other facts can you tell me about how she worked with the african-american community?
Sanger was an honorary delegate of the Birth Control Federation of America, which included a supervisory role.

Question: When did she stop working with birth control federation of america?
Self-contained rewrite: When did Margaret Sanger stop working with birth control federation of america?