Edward Jenner spread around Europe and was used "en masse" in the Spanish Balmis Expedition (1803–1806), a three-year-long mission to the Americas, the Philippines, Macao, China, led by Dr. Francisco Javier de Balmis with the aim of giving thousands the smallpox vaccine. The expedition was successful, and Jenner wrote, "I don’t imagine the annals of history furnish an example of philanthropy so noble, so extensive as this." Napoleon, who at the time was at war with Britain, had all his French troops vaccinated, awarded Jenner a medal, and at the request of Jenner he released two English prisoners of war and permitted
Jenner, California build a house in what became known as Jenner Gulch, the site of the town. Stillwater Cove Regional Park, located north of Jenner, features picnic facilities, beach access, and a historic one-room schoolhouse. Jenner received media attention in 2004 after the bodies of Lindsay Cutshall and Jason S. Allen were discovered on Fish Head Beach just north of town. The incident became known as the Jenner, California double-murder of 2004. According to the United States Census Bureau, the CDP covers an area of 2.4 square miles (6.2 km²), 2.1 square miles (5.5 km²) of it land, and 0.3 square miles