The date is uncertain, but Charles Dickens and Edgar A. Poe met some time in March 1842, likely March 7.
As part of his tour of the United States, Dickens arrived in Philadelphia on March 5 and lodged at the United States Hotel on Chestnut Street above Fourth Street. By this time, Dickens had published a handful of works, including Oliver Twist, The Life and Adventures of Nicholas Nickleby, and Barnaby Rudge: A Tale of the Riots of 'Eighty (his A Christmas Carol would be published in 1843). Poe saw a great opportunity to rub elbows with an admired literary figure and wrote him a letter requesting an interview. Dickens responded with his own letter, dated March 6, 1842:
I shall be very glad to see you, whenever you will do me the favor to call... I have glanced over the books [apparently a copy of Tales of the Grotesque and the Arabesque] you have been so kind as to send to me; and more particularly at the papers to which you called my attention [Poe's review of Barnaby Rudge] . I have the greater pleasure in expressing a desire to see you, on their account.
Presumably, the two writers met on March 7, likely at the United States Hotel where Dickens was staying. The major topic of discussion was the state of American poetry. Poe read to Dickens a poem called "A Humble Bee" by Ralph Waldo Emerson. Dickens, apparently a sincere admirer of Poe's works which he "glanced over," offered to find an English publisher for Tales of the Grotesque and Arabesque (he never did). And Poe, always thinking like an editor, tried to convince Dickens to write for Graham's Magazine - Dickens slyly responded that he would, if he contributed to any American magazine.
By March 9, Dickens left Philadelphia and made his way to Washington, D.C., the next leg of his United States visit.
For more on the connection between Poe and Dickens, please read my prior post on "Charles Dickens with his raven."