To put Angelou's work into a historical context, you will need to know something about the Civil Rights Movement in the U.S. Here's a good general introduction to segregation and Jim Crow from The Columbia Encyclopedia, as well as some related links.
Here is some information about a film that Angelou directed in 1998 called Down in the Delta. How do you think her work here relates to her writing?
To expand your knowledge about this author's personal history, consult this chronology of recent events in her life from her official website.
Interested in Angelou's collaboration with other artists? This site provides some information about her collaboration with the painter Jean-Paul Basquiat.