I think that this question is probably going to need more specificity in its answer. From the most general points of view, I think that the work of Walker and Angelou differ from African- American male writers because of the inclusion of gender as a way to view reality. African- American male writers of the time period such as Baldwin or Wright speak to a larger condition of race/ ethnicity in American society. Yet, the issue of gender is one that is not fully explored. Perhaps, this can be credited to the time period, where race and ethnicity, especially on the part of men, were seen as the defining issue of the day. The battle over Jim Crow and segregation, norther "covert" racism, and the fight for Civil Rights placed a primacy on race as the defining issue in American political and social discourse. The issue of gender is not going to be fully integrated into social activism until a later point.
However, much of this will start or reside in the works of Angelou and Walker. These authors infused gender into the argument alongside race. Their work differs on this level. When Walker writes about identity reclamation, she writes on a level that embraces both gender and race as elements that converge and work with one another, requiring a dual explication. When Angelou knows "why the caged bird sings," she explores this on grounds of race and gender, and not simply one or the other. Writers like Angelou and Walker are some of the first writers to make the assertion that social construction of identity takes place on multiple levels, and not simply on one. Women of color, thus, were able to formulate how the winds of change were able to blow and uncover their lives as both beings of gender and race and in this, Walker and Angelou's work serves to be fundamentally different than their male counterparts of the time period.