This paper presents historical facts, pivotal figures, and significant locations that led to the development of the Bacillus Calmette-Guerin (BCG) vaccine at the turn of the 20th century to combat tuberculosis. We reviewed historical publications and gathered original data about the co-inventors, Albert Calmette and Camille Guerin, and the birthplace of their discovery, the Pasteur Institute of Lille, France. This historical overview highlights the co-inventors’ distinct personalities and the local political drive to unify scientific efforts to rid the northern region of France of contagious diseases. Owing to their relentless dedication, the vaccine is aptly named after its creators. It is a fitting tribute, as Calmette and Guerin combined their expertise, courage, and determination to develop this exceptional preventive medicine. This review underscores their contributions to the creation of the BCG vaccine and their lasting impact.