P.'s Correspondence" is a short story by t Nathaniel Hawthorne, constituting a pioneering work of alternate history. Some consider it the very first such work in the English language.

The story uses the technique of the false document, common in literature of the period. It purports to transcribe a letter written by a mentally-deranged friend of the writer, identified only by the initial "P." (supposedly to protect his privacy). As presented in the preface, the writer seems to share with the rest of the world the belief that his friend is indeed mad, and publishes the text as an act of kindness rather than out of believing in its veracity.

However, the text attributed to P. is far from looking like the ravings of a madman. Rather, it seems the product of a rational and sensitive mind placed in the impossible situation of simultaneously perceiving two realities which contradict each other in numerous important details, having no explanation for this phenomenon, and being increasingly unable to decide which is true and which is imaginary. (Summary by Wikipedia)