The relationship between cousins Neilson and Edgar Poe is one of the many impenetrable mysteries in the latter's biography. Neilson, so far as can be documented, always treated his famous relative in a respectful, if not laudatory manner. As early as 1830, he wrote to his fiancee, Josephine Clemm (the half-sister of Edgar's future wife,) "Edgar Poe has published a volume of Poems one of which is dedicated to John Neal the great autocrat of critics--Neal has accordingly published Edgar as a Poet of great genius etc.--Our name will be a great one yet." In the years following Edgar's death, Neilson's comments about him, both public and private, continued to be consistently supportive. He appeared to treat Maria Clemm, now left alone in the world, with kindness and sympathy, for which she was quite grateful. He even planned to write Edgar's biography, but was described by a friend as too "dilatory" to ever complete the project.
In return, Edgar hated him, with a passion surpassed only by his loathing for Thomas Dunn English and Elizabeth Ellet. In his well-known and quite astonishing letter to Maria Clemm in August of 1835, he reacted to the news that Neilson and Josephine Poe had offered to provide a secure home for her daughter Virginia (and perhaps Maria as well) with what seems an inexplicable panic. He endeavored to convince his aunt that this apparently generous and benign offer from Virginia's sister and brother-in-law was really part of some sinister plot to permanently separate him from the girl he loved. "[W]hen Virginia goes with N. P....I shall never behold her again--that is absolutely sure." He spoke of the proposal as one that would inevitably bring misery, not only to him, but to Virginia as well: "I do sincerely believe that your comforts will for the present be secured--I cannot speak as regards your peace--your happiness." He regarded Mrs. Clemm's willingness to even listen to this plan as "cruel," a betrayal that "wounds me to the soul."
How did he arrive at the conviction that Neilson and his wife were determined to keep Virginia away from him for good? So far as is known, they did not have a close relationship with the Clemm ladies, and surely they would have considered Virginia's matrimonial plans--assuming they even knew of them, which is not at all certain--to be the concern of her and her mother, not themselves. (For what it's worth, Neilson Poe was once quoted as having said that he never knew why Virginia turned down his offer until Maria Clemm showed him Edgar's letter many years later.)
In an 1839 letter to Joseph Snodgrass, Edgar referred to “the feelings of ill will toward me which are somewhat prevalent (God only knows why) in Baltimore.” In a subsequent letter to this same correspondent, he elaborated upon this statement, making it clear that he saw his Baltimore cousin as at least partially responsible for this "ill will," describing "N.P." as "the bitterest enemy I have in the world," adding that, "He is the more despicable in this, since he makes loud professions of friendship." Edgar claimed not to know the reason for his cousin's animosity, only suggesting that it may have been jealousy over his literary career. It has been rather vaguely suggested that Edgar's puzzling show of hostility arose from lingering bitterness over Neilson's offer to act as Virginia's protector, or perhaps from Neilson's failure (either through inability or disinclination) to provide Edgar with loans or literary favors. Such reasons seem hardly sufficient to explain the harshness of the poet's attitude towards this relative he seemingly barely knew.
His one surviving letter to Neilson, written in August 1845, is very civil, but decidedly cool. He responded to his cousin's evident friendly overtures with a bland courtesy, assenting that it was indeed a pity that their two families were estranged, but he showed no sincere desire to amend that situation. The letter also indicated that Neilson and his family were unaware that for the past three years, Virginia had been battling a hopeless illness (which Poe always mysteriously called "the accident")--a striking sign of just how alienated they were from her life.
How did this alienation arise? Edgar Poe was emotionally hyper-sensitive and frequently hyperbolic in his speech, but he was not a paranoiac. If he usually thought that the world was out to get him, it was only because the world usually was. He saw cousin Neilson not merely as someone he disliked, but as a malignant enemy. It seems impossible that he could have come to such a radical conclusion purely out of thin air, but it is equally impossible to trace the source of this conviction.
Who was Neilson Poe? A terribly misjudged friend or a secret foe? Was Edgar drastically, almost insanely, wrong about his cousin? Or could Neilson have been, virtually from the beginning, a player in some dark, hidden game of which history now knows nothing?