A neurosurgical reappraisal of President Lincoln's fatal cranial injury.

President Abraham Abraham Lincoln's assassination in April 1865 remains one of the most scrutinized cases in forensic history. We re-examined his fatal head wound through the lens of modern neurosurgery, focusing on projectile trajectory, biomechanics, skull base anatomy, fluid percussion, and periorbital injury, and including the use of artificial intelligence search. A systematic review was conducted using PubMed (n = 19) and Scopus (n = 12), along with 5 additional sources available on the Internet. Following PRISMA guidelines, 3 original studies were included. Historical autopsy documents were analyzed alongside contemporary literature. Generative AI models (Gemini, Claude, Perplexity, ChatGPT) were used to assist in triangulating ballistic and clinical interpretations. Separate autopsy reports by Woodward, Curtis, and Stone confirm a left occipital entry wound, with the bullet traveling posterior-anterior through the left hemisphere and lodging above the corpus striatum. The absence of midline crossover is consistent across modern reconstructions. Bilateral orbital fractures and right-sided ecchymosis are best attributed to heightened pressure-wave dynamics, not to direct trauma or contrecoup effects. Lincoln's injury represents a non-survivable low-velocity penetrating brain injury. The forensic and neurosurgical evidence supports a strictly left-sided trajectory, possible basal skull fractures, and pressure-driven orbital injury.