This thesis explores the major themes of William Cullen Bryant's poetry. Chapter II focuses on Bryant's poetic theory and secondary criticism of his theory. Chapter III addresses Bryant's religious beliefs, including death and immortality of the soul, and shows how these beliefs are illustrated by his poetry. A discussion of the American Indian is the subject of Chapter IV, concentrating on Bryant's use of the Indian as a Romantic ideal as well as his more realistic treatment of the Indian in The New York Evening Post. Chapter V, the keystone chapter, discusses Bryant's scientific knowledge and poetic use of natural phenomena. Bryant's religious beliefs and his belief in nature as a teacher are also covered in this chapter.