In I Know Why the Caged Bird Sings and The Color Purple, what are the similarities in these women's writings?

To add to the above answer, a literal comparison between
I Know Why the Caged Bird Sings and The Color Purple
is the exploration of sexual violence that both books address.  In the first
text, eight-year-old Maya is raped by Mr. Freeman, her mother's boyfriend.  The
horrifying experience causes Maya to become reclusive, and she shuts everyone out of her
world except her brother, Bailey.  Maya is robbed of her identity and feels like she has
no place in the world.  Similarly, in The Color Purple, Celie is
raped by her father and is forced to bear his children.  Celie endures repeated sexual
abuse by her father until she is sent into a marriage with Albert.  Celie also feels
like her life means little, and she retreats into herself, expressing her thoughts only
through letters to God, and later to her sister, Nettie.  Maya and Celie eventually find
their inner beauty through close relationships with other women, Ms. Flowers for Maya,
and Shug Avery for Celie.