On March 4, 1919, medical reports recorded what is generally recognized as the first documented outbreak of foodborne botulism in the United States associated with improperly canned ham. The incident occurred in the wake of widespread home food preservation during and after World War I, when home canning practices increased and understanding of microbial foodborne hazards remained limited. Clostridium botulinum, the bacterium that produces the potent botulinum neurotoxin, had only recently been identified in the late 19th and early 20th centuries. Early clinical descriptions of botulism—so named from the Latin botulus (sausage), reflecting earlier European sausage-associated cases—had established a pattern of descending flaccid paralysis, dysphagia, and visual disturbances. By 1919, physicians were beginning to connect such clinical syndromes with contaminated preserved foods in North America. The 1919 U.S. outbreak involved several cases of severe paralytic illness following consumption of home-canned ham. Contemporary public health and medical accounts linked the episode to inadequate sterilization during home canning, which allowed survival of C. botulinum spores and subsequent anaerobic toxin production in the sealed jars. Patients presented with symptoms consistent with botulism: blurred vision, difficulty swallowing, dry mouth, muscle weakness, and progressive respiratory compromise in severe cases. At the time, diagnostic laboratory methods were primitive compared with modern standards. Clinical recognition and epidemiologic linkage to a common food vehicle were central to identifying the outbreak’s cause. The event contributed to increasing awareness among physicians, public health officials, and the public about the dangers of improper home canning and the need for safer preservation methods. In the decades that followed, research into botulism advanced considerably. The bacterium’s toxin was characterized, animal-tested assays and, later, mouse bioassays became tools for laboratory confirmation, and canning protocols were refined to include pressure canning and recommended heat treatments to inactivate spores. Public health guidance and canned-food safety standards evolved, drastically reducing the incidence of foodborne botulism from home-preserved foods in many countries. Historical accounts of the 1919 outbreak are based on contemporaneous medical and public health reports; some details—such as the exact number of affected individuals, precise laboratory confirmation by modern standards, or full patient outcomes—are incomplete or were not documented with the rigor expected today. Nevertheless, the March 4, 1919 event remains significant as an early, documented recognition in the United States that improperly canned meats can cause life-threatening botulism, helping to shape subsequent food-safety recommendations. Today, botulism remains rare but potentially lethal. Prevention focuses on proper canning techniques (including pressure canning for low-acid foods), prompt disposal of bulging or leaking cans and jars, and public education. The 1919 outbreak is a historical reminder of how advances in microbiology and public health practices have reduced risk, while also underscoring the continuing importance of safe food-preservation techniques.