The author of the excerpt is? 'Lift every voice and sing, Till earth and heaven ring, Ring with the harmonies of Liberty; Let our rejoicing rise High as the list ning skies, Let it resound loud as the rolling sea.Sing a song full of the faith that the dark past has taught us, Sing a song full of the hope that the present has brought us; Facing the rising sun of our new day begun,Let us march on till victory is won.'

Ralph Waldo Emerson was a prominent American essayist and poet known for his transcendentalist beliefs and works, such as "Nature" and "Self-Reliance." However, he did not write "Lift Every Voice and Sing," which is focused on the African American struggle for freedom and hope.

Harriet Beecher Stowe is best known for her novel "Uncle Tom's Cabin," which highlighted the moral issues of slavery. While her contributions to abolitionist literature are significant, she is not the author of the excerpt in question.

Margaret Walker was an influential poet and novelist, particularly known for her poem "For My People." Although her work addresses similar themes of racial identity and empowerment, she did not write "Lift Every Voice and Sing."

George Moses Horton was an enslaved African American poet known for his works that expressed his longing for freedom. Despite his notable contributions to American literature, he is not the author of the excerpt provided.