In mid-April 1976 physicians in Yambuku, a village near the Ebola River in then-Zaire (now the Democratic Republic of Congo), reported an unusual cluster of severe febrile illness marked by high fevers, vomiting, diarrhea and bleeding. On April 12, 1976, clinicians recognized the outbreak as a distinct and unusually lethal disease. Over the following weeks, local health workers and Belgian colonial-era medical staff documented a rapidly progressing illness that caused high fatality rates among patients and some of their caregivers. Investigations conducted by Congolese and international teams identified a previously unknown filovirus as the causative agent. The virus was later named Ebola, after the nearby river, to avoid stigmatizing the village of Yambuku. Early fieldwork revealed nosocomial amplification: contaminated needles and inadequate infection-control practices in the Yambuku Mission Hospital contributed to transmission among patients and medical staff. Traditional funeral practices that involved close contact with the deceased also likely facilitated spread. The 1976 outbreak was notable for its severity and for the rapid public-health response it prompted. Samples taken from patients were analyzed by laboratories in Belgium and elsewhere, which isolated the novel virus and characterized its morphology and pathology. The outbreak ultimately involved several dozen confirmed and probable cases in the Yambuku area, with a case fatality rate reported at roughly 88 percent in those early records, though case counts and exact mortality figures vary among contemporary reports. Parallel to the outbreak in Yambuku, later in 1976 a separate, simultaneous outbreak occurred in Nzara, Sudan (now in South Sudan), caused by a distinct strain of the same virus family. Those two 1976 events established Ebola virus disease as a serious, emergent infectious threat and set the stage for subsequent research into filoviruses, clinical management, and infection-control measures. The 1976 response highlighted several lessons: the importance of safe injection and hospital hygiene practices, the need for rapid laboratory identification and international collaboration, and the role of cultural practices in transmission dynamics. The outbreak stimulated virological research that would, over decades, clarify Ebola’s reservoirs (with bats now considered likely natural hosts), modes of transmission (direct contact with bodily fluids and contaminated materials), and potential treatment and prevention strategies. Historical records from 1976 include medical reports, field notes, laboratory analyses and contemporaneous communications among health authorities. Some details—such as precise case counts, chains of transmission, and the initial index case—remain subject to uncertainty or variation among sources. Nevertheless, the April 1976 recognition of this hemorrhagic fever marks the first documented identification of Ebola virus disease in the medical literature and public-health records. The legacy of the 1976 outbreaks continues to influence global health: protocols for personal protective equipment, outbreak investigation, and community engagement were developed and refined in response to early Ebola events. Subsequent outbreaks, research advances and the eventual development of vaccines and therapeutics build on knowledge that began with those first documented cases in 1976.