May W. Stanchfield (Tennison) was 18 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.
May W. Stanchfield (Tennison) was 25 years old when Albert Einstein publishes his first paper on the special theory of relativity. Albert Einstein was a German-born theoretical physicist who developed the theory of relativity, one of the two pillars of modern physics. His work is also known for its influence on the philosophy of science. He is best known to the general public for his mass–energy equivalence formula E = mc2, which has been dubbed "the world's most famous equation". He received the 1921 Nobel Prize in Physics "for his services to theoretical physics, and especially for his discovery of the law of the photoelectric effect", a pivotal step in the development of quantum theory.
May W. Stanchfield (Tennison) was 34 years old when Archduke Franz Ferdinand and his wife, Sophie, Duchess of Hohenberg, were assassinated by a Yugoslav nationalist named Gavrilo Princip in Sarajevo, sparking the outbreak of World War I. Archduke Franz Ferdinand, Archduke of Austria-Este was a member of the imperial Habsburg dynasty, and from 1896 until his death the heir presumptive (Thronfolger) to the Austro-Hungarian throne. His assassination in Sarajevo precipitated Austria-Hungary's declaration of war against Serbia, which in turn triggered a series of events that resulted in Austria-Hungary's allies and Serbia's declaring war on each other, starting World War I.
May W. Stanchfield (Tennison) was 40 years old when The Nineteenth Amendment to the United States Constitution was ratified, guaranteeing women's suffrage in America. The Nineteenth Amendment to the United States Constitution prohibits the states and the federal government from denying the right to vote to citizens of the United States on the basis of sex. It was adopted on August 18, 1920.
May W. Stanchfield (Tennison) was 50 years old when Great Depression: In a State of the Union message, U.S. President Herbert Hoover proposes a $150 million (equivalent to $2,197,000,000 in 2017) public works program to help generate jobs and stimulate the economy. The Great Depression was a severe worldwide economic depression that took place mostly during the 1930s, beginning in the United States. The timing of the Great Depression varied across nations; in most countries it started in 1929 and lasted until the late-1930s. It was the longest, deepest, and most widespread depression of the 20th century. In the 21st century, the Great Depression is commonly used as an example of how far the world's economy can decline.
May W. Stanchfield (Tennison) died in 1945 at the age of 65