A continent turns into a woman. A placid land is pillaged by invading forces. Entire peoples are changed utterly by the violence of religion and warfare. Weak people (and nations) begin to become powerful forces. There are transformations all over this poem, folks. Given the short number of lines, it's actually pretty remarkable how much is going on.
Angelou overlooks the problems of present-day Africa because the only way to understand the present is to look at the past.
The Africa in the beginning of the poem is a sad one, with tears for eyes and deserts for hair. Angelou shows its transformation from a wounded continent to one that is "rising."