David W. Hennessy was 12 years old when Louis Pasteur successfully tests his vaccine against rabies on Joseph Meister, a boy who was bitten by a rabid dog. Louis Pasteur was a French biologist, microbiologist and chemist renowned for his discoveries of the principles of vaccination, microbial fermentation and pasteurization. He is remembered for his remarkable breakthroughs in the causes and prevention of diseases, and his discoveries have saved many lives ever since. He reduced mortality from puerperal fever, and created the first vaccines for rabies and anthrax. His medical discoveries provided direct support for the germ theory of disease and its application in clinical medicine. He is best known to the general public for his invention of the technique of treating milk and wine to stop bacterial contamination, a process now called pasteurization. He is regarded as one of the three main founders of bacteriology, together with Ferdinand Cohn and Robert Koch, and is popularly known as the "father of microbiology".
David W. Hennessy was 25 years old when Spanish–American War: The Treaty of Paris is signed, officially ending the conflict. The Spanish–American War was fought between the United States and Spain in 1898. Hostilities began in the aftermath of the internal explosion of the USS Maine in Havana Harbor in Cuba, leading to US intervention in the Cuban War of Independence. American acquisition of Spain's Pacific possessions led to its involvement in the Philippine Revolution and ultimately in the Philippine–American War.
David W. Hennessy was 35 years old when Ford puts the Model T car on the market at a price of US$825. Ford Motor Company is an American multinational automaker headquartered in Dearborn, Michigan, a suburb of Detroit. It was founded by Henry Ford and incorporated on June 16, 1903. The company sells automobiles and commercial vehicles under the Ford brand and most luxury cars under the Lincoln brand. Ford also owns Brazilian SUV manufacturer Troller, an 8% stake in Aston Martin of the United Kingdom, and a 49% stake in Jiangling Motors of China. It also has joint-ventures in China, Taiwan, Thailand, Turkey, and Russia. The company is listed on the New York Stock Exchange and is controlled by the Ford family; they have minority ownership but the majority of the voting power.
David W. Hennessy was 39 years old when The British passenger liner RMS Titanic sinks in the North Atlantic at 2:20 a.m., two hours and forty minutes after hitting an iceberg. Only 710 of 2,227 passengers and crew on board survive. RMS Titanic was a British passenger liner that sank in the North Atlantic Ocean in the early hours of 15 April 1912, after colliding with an iceberg during its maiden voyage from Southampton to New York City. There were an estimated 2,224 passengers and crew aboard, and more than 1,500 died, making it one of the deadliest commercial peacetime maritime disasters in modern history. RMS Titanic was the largest ship afloat at the time it entered service and was the second of three Olympic-class ocean liners operated by the White Star Line. It was built by the Harland and Wolff shipyard in Belfast. Thomas Andrews, her architect, died in the disaster.