In 1825 he published Travels in the Central Portions of the Mississippi Valley, and in 1839 appeared his Algic Researches, containing Indian legends, notably, "The Myth of Hiawatha and other Oral Legends."
In 1854 hejresigned his professorship. In the following year he gave to the world the Indian Edda, The Song of Hiawatha, a conscious imitation, both in subject and metre, of the Finnish epic, the Kalevala, with which he had become acquainted during his second visit to Europe.
His mode of treatment is subjective and lyric. No matter what form his works assume, whether the epic, as in Evangeline, The Courtship of Miles Standish and Hiawatha, the dramatic, as in The Spanish Student, The Golden Legend and The Mask of Pandora, or the didactic, as in The Psalm of Life and many of the minor poems; they are all subjective.
One warm, sunny day in early spring, when we were at the North, the balmy atmosphere appears to have brought to her mind the sentiment expressed by Longfellow in "Hiawatha," and she almost sings with the poet: "The ground was all aquiver with the stir of new life.
Schoolcraft in his Adgic Researches (1839), upon which Longfellow founded his "Hiawatha."