In late 19th‑century neurology, clinicians increasingly connected brain injury with specific alterations of memory and cognition. A widely cited early report dates to 21 February 1887, when physicians described a patient who, after a traumatic head injury, exhibited both loss of past memories (retrograde amnesia) and difficulty forming new memories (anterograde amnesia). Although earlier anecdotes and case notes about memory loss after head trauma exist, the 1887 account is notable for its clinical detail and for being circulated within the medical literature of the period, contributing to the emerging clinical category of post‑traumatic amnesia. The patient in this report had sustained a substantial blow to the head. Following the injury, examiners recorded a disturbed state of consciousness and a marked disturbance of memory: the patient could not recall events from before the injury and had impaired capacity to retain new information. The clinicians who published the case carefully documented the time course of symptoms and repeated assessments of the patient’s memory functions, distinguishing transient confusion from a more persistent amnestic syndrome. Such differentiation helped clinicians recognize that some memory disturbances after trauma were not mere delirium but might reflect more enduring dysfunction of memory systems. This 1887 case was part of a broader shift in medical thinking. Advances in neuropathology, growing familiarity with battlefield wounds, and systematic clinical observation encouraged physicians to link localized brain damage with discrete cognitive deficits. The clinical description of amnesia after head injury informed later work by neurologists and neuropsychologists who sought to map memory functions to brain structures and to define prognostic features of recovery. Historians caution that labeling any single 1887 report as the absolute “first” is problematic. Earlier clinicians—working in different languages and medical traditions—had recorded patients with memory disturbances after blows to the head, but those accounts were often brief, scattered in casebooks, or framed in terms that later clinicians judged imprecise. The 21 February 1887 publication stands out because it appeared in the organized medical literature with clear clinical characterization, which allowed contemporaries and successors to cite and build on it. The significance of the 1887 case lies less in being an isolated discovery than in marking an inflection point: clinicians were moving toward systematic description, classification, and prognostication of amnesia following trauma. Subsequent research in the 20th century elaborated neuroanatomical causes (for example, diffuse axonal injury and damage to medial temporal structures) and clarified distinctions among transient post‑traumatic confusion, post‑traumatic amnesia (duration‑based), and more chronic organic amnestic syndromes. Today clinicians still use the concept of post‑traumatic amnesia as a prognostic indicator after traumatic brain injury, measuring its duration as one factor in outcome prediction. When referencing historical milestones, scholars therefore treat the 21 February 1887 report as an important early, well‑documented case that helped shape clinical recognition of memory disorders after head trauma, while acknowledging antecedent reports and the gradual nature of medical progress.