Edward Wagenknecht, "Longfellow, Henry Wadsworth," American National Biography Online, February 2000, http://www.anb.org/articles/16/16-01015.html.
Longfellow's literary reputation, like [Alfred] Tennyson's, has suffered from the inevitable changes in poetic style and taste. He has been called too didactic, but when he began writing he was widely blamed for sacrificing uplift to purely aesthetic considerations. "A Psalm of Life" (1839) seems one of his poorest poems, but his contemporaries, including the French poet Charles Baudelaire, found it deeply moving. An impatient reader and writer, Longfellow wanted everything stated as quickly and as plainly as possible, not left to implication and inference.