Poe wrote to Sarah Josepha Hale, herself a well-known literary figure and author of the children's poem Mary Had a Little Lamb, to decline an invitation to publish an article in a magazine she edited at the time.

"You usually don't see a lengthy handwritten letter like this by Poe," said Bobby Livingston, vice president of RR Auctions, a New Hampshire-based firm which handled the transaction on Wednesday.

"To have him writing to the author of Mary Had a Little Lamb is pretty amazing."

Written eight years before he published his most famous poem, The Raven, Poe, then a literary critic for a magazine in Richmond, Virginia, tells Hale he is too busy with other work after a recent illness.

"To send you a crude or hastily written article would be injurious to me, and an insult to yourself - and I fear that I could, at present, do little more," Poe wrote.

Godey's Lady's Book, the magazine Hale edited, was among the most popular of the period and published writers including Nathaniel Hawthorne, Oliver Wendell Holmes and Washington Irving. Hale is also known for her role advocating the creation of a Thanksgiving holiday in the United States.

The letter was purchased by a West Coast collector who wished to remain anonymous. The first eight stanzas of the poem For Annie written in Poe's hand sold for R 5.78 million in 2009.