On April 16, 1841, the first large-scale outbreak of Canton Madness occurred in Canton, China. The city was under multiple influences at the time and was ripe for the spread of an infectious disease; the Opium War, the British and Merchants were all coming and going from Canton. It is believed that this outbreak catapulted the disease from Canton to the rest of the world, making it one of the most important outbreaks in history.