Hawthorne, Nathaniel. "P.'s Correspondence".
What if: Byron, Burns and Shelley lived longer lives, but Dickens died early.
Summary: A letter describes encounters with various literary and political figures during the 1840s.
Comments: First known English language alternate history short story, although the introduction sidesteps the matter by presenting the work as the product of a deranged mind. The first known allohistorical novel in English would appear to be Benjamin Disraeli's 1833 Alroy, q.v.

Published: In United States Magazine and Democratic Review, April 1845; Mosses from an Old Manse, Wiley & Putnam 1846, Putnam's 1851, Ticknor & Fields 1854, 1865, Fields, Osgood 1871, Houghton, Osgood 1880, Houghton, Mifflin 1883, 1893, H. Altemus 1893, T.Y. Crowell 1903, Books for Libraries 1970 (0836935500), Modern Library 2003 (0812966058); and Complete Works, Vol. 2, Houghton-Mifflin 1882.
Original in: English.
Translation: Italian by Paola Frandini as "Una lettera di P.", in Racconti dell'ombra e del mistero, Theoria 1993 (8824103235).
Bookstore: Listed by Amazon.com in hardcover (Mosses from an Old Manse) and in paperback (Mosses from an Old Manse).