Longfellow is far more famous as a poet, and his most famous stories—Evangeline and Hiawatha—were written in verse. He did, however, write in prose as well. His romances have been largely forgotten, though the poet's reputation kept them running through edition after edition through most of the latter nineteenth century.
Hyperion, a romance. By the author of "Outre-Mer." New York: Published by Samuel Colman, 1839. —This first edition is exceedingly rare, since the publisher failed, and half the edition was seized by creditors. Longfellow revised the text somewhat in later editions. We have cobbled together a complete set from a copy of the first volume (in a very good scan) at archive.org and a copy of the second at Google Books.
Volume I (at archive.org).Hyperion: A Romance. By Henry Wadsworth Longfellow. Revised edition. Boston: James R. Osgood and Company, 1871.
Volume II (at Google Books).
Hyperion: A Romance. By Henry Wadsworth Longfellow. Revised edition. Illustrated. Philadelphia: David McKay (no date, but probably about 1900). —At archive.org. Illustrated with photographs of the picturesque locations mentioned in the romance.
The Romance of Hyperion must not be judged by the principles of classical composition. It belongs, pre-eminently, to the Romantic School. The scene is laid in the very centre of all that is romantic in the land of recollections and ruins of the Middle Ages. It is steeped in the romantic spirit. The language is moulded into the gorgeous forms of Gothic art. The illustrations and comparisons are drawn wholly from the sphere of romantic literature. In tender and profound feeling, and in brilliancy of imagery, the work will bear a comparison with the first productions of romantic fiction, which English literature can boast. Some tastes will be offended by the luxuriance of the language, and the brocaded aspect which it occasionally presents. A mind educated in exclusive admiration of the ancient classics, or in the modern schools formed upon their principles, may naturally be displeased with many things which occur in "Hyperion." We are ourselves by no means insensible to the force of strictures, which may be made upon it. But we remember, on the other hand, that nature is limited to no age or country; and art may select from the whole range of nature those objects which suit her purposes, whether they have been handled by the ancient masters or not, provided she do not transcend the limits of morality on the one side, nor sink to the region of commonplace, on the other. "Hyperion" must be judged wholly with reference to this view. The term romance has probably misled a great many readers. We have been accustomed to expect, in a work bearing this title, a prodigious amount of diabolical mysteries, trap-doors without number, subterranean dungeons, and the clanking of chains; fortunate, if we escaped with half a dozen ghosts, to say nothing of wizards and enchanters. Mailed knights, and dragon-guarded ladies, are also quite necessary ingredients in the genuine mixture called a romance. "Hyperion" is no romance of this description. Its quiet, delicate, and beautiful pictures contrast with the terrific scenes of old romance, like a soft, autumnal scene, compared with the landscape swept by the tropical hurricane.
——"A Critique of Hyperion, Extracted from the North American Review," in the Corsair, Vol. I, No. 46 (January 25, 1840).
Kavanagh, a tale. By Henry Wadsworth Longfellow. Boston: Ticknor, Reed, and Fields, 1849.
Hyperion and Kavanagh by Henry Wadsworth Loongfellow. Boston and New York: Houghton, Mifflin and Company, 1898.