Edgar Allan Poe made significant literary contributions to American literature through his mastery of gothic fiction and the short story format. His works, such as "The Tell-Tale Heart" and "The Fall of the House of Usher," introduced psychological depth and innovative narrative techniques, influencing the genre profoundly. Poe is also credited with popularizing the detective story through "The Murders in the Rue Morgue," laying the groundwork for future mystery literature. Additionally, his poem "The Raven" showcased his unique ability to blend rhythm and language, solidifying his position as a key figure in both poetry and prose.