William Faulkner’s notable achievements in American literature include his innovative narrative techniques and his exploration of complex themes such as race, time, and identity. His pioneering use of stream of consciousness allowed for intricate character development and deep psychological insights. Faulkner's works, particularly those set in the American South, such as "The Sound and the Fury" and "As I Lay Dying," captured the region’s social fabric and historical struggles. He received the Nobel Prize in Literature in 1949, cementing his legacy as one of the most influential writers in American history.