Final answer:
Frances Ellen Watkins Harper supported the abolitionist movement by writing poetry and delivering lectures against slavery.
Step-by-step explanation:
Frances Ellen Watkins Harper was a free Black woman who made significant contributions to the abolitionist movement primarily through her literary work and as a speaker. Among her many efforts to combat slavery, Harper is best known for publishing poetry and giving anti-slavery lectures. Her work shed light on the injustices of slavery and she used her writing and public speaking skills to advocate for the abolition of slavery as well as for civil rights and women's rights.