To understand what so sets Poe's "The Fall of the House of Usher" apart from other works of the time, we should consider the kind of literature that was popular then.
At a time when most popular literature was highly moralistic, Poe's stories were concerned only with creating emotional effects.
Poe felt that most writers concentrated on making "religious or political statements," but sacrificed the integrity of the writing in doing so. Poe wasn't interested in preaching or conveying a theme. He entertained his readers. The emotional response he garnered was not based on high intrigue or a devastating love affair gone wrong. He focused on stories that evoked fear, terror and confusion: for his characters were often insane—
[Poe wrote] tales of terror, in which he often depicted the psychological disintegration of unstable or emotionally overwrought characters...
Poe was not acknowledged by his peers for his divergent literary path. However, the short story became an acceptable literary form. Poe's artistry is clear in his ability to tell a complete story with "horrific" results in so few pages.
"The Fall of the House of Usher" has hallmark elements of Poe's work: the hint of insanity, obsession, gloom, premonitions of evil— and the foreshadowing of disaster (which is complete as the house seems to destroy itself at the end). However, one aspect of this story that I believe stands out from the rest—which reflects a popular fear of Poe's time—is the fear of being buried alive. Because medical science had not advanced far enough to detect the subtle presence of life, it was not unusual that someone had been buried before death:
This fear was so prevalent at the time that special coffins or methods of alerting the living above ground were invented and implemented to stop mistaken burial:
A safety coffin or security coffin is a coffin fitted with a mechanism to prevent premature burial or allow the occupant to signal that he/ she has been buried alive.
Victorians have been noted to have had a heightened fear of such an event, and many took precautions to prevent such a horrible fate. While some state that actual "premature burials" have been exaggerated, others cite events documented as early as the 14th Century.
Of course, other aspects of this story that may horrify and also fascinate include inferences to long-standing inbreeding and incest, which may be responsible for Roderick Usher's illness as well as his sister's illness and impending death—at which point Roderick will be "the last of the ancient race of the Ushers." A similar "closeness" may exist between Roderick and Madeline, his...
...tenderly beloved sister—his sole companion for long years—his last and only relative on earth.
Madeline seems to be ghost-like or one already dead—in more modern contexts, the question has been asked: was she a vampire?
...the lady Madeline...passed slowly through a remote portion of the apartment, and, without having noticed my presence, disappeared.
The ultimate horror reflects her premature burial. First her brother's fear...
We have put her living in the tomb!
...and then, the actuality...
...there did stand the lofty and enshrouded figure of the lady Madeline of Usher...
These elements make the story eerily fascinating even today.